CHEM 122 - GENERAL CHEMISTRY II -
Quantitative chemistry Question Bank
Question 1
Step-by-step solution: 1. Determine the molar mass of CaCl2: - The molar
mass of Ca is 40.08 g/mol - The molar mass of Cl is 35.45 g/mol (there are 2
Cl atoms in CaCl2) - Molar mass of CaCl2 = 40.08 g/mol + 2(35.45 g/mol) =
40.08 g/mol + 70.90 g/mol = 110.98 g/mol
2. Use the formula: number of moles = mass (g) / molar mass to calculate
the mass: - 0.25 moles = mass (g) / 110.98 g/mol - Mass (g) = 0.25 moles x
110.98 g/mol - Mass (g) = 27.745 g
Therefore, the mass in grams of 0.25 moles of calcium chloride (CaCl2) is
27.745 grams.Question 1: Calculate the mass in grams of 0.25 moles of
calcium chloride (CaCl2).
Step-by-step solution: 1. Determine the molar mass of CaCl2: -
The molar mass of Ca is 40.08 g/mol - The molar mass of Cl is 35.45
g/mol (there are 2 Cl atoms in CaCl2) - Molar mass of CaCl2 = 40.08
g/mol + 2(35.45 g/mol) = 40.08 g/mol + 70.90 g/mol = 110.98 g/mol
2. Use the formula: number of moles = mass (g) / molar mass to
calculate the mass: - 0.25 moles = mass (g) / 110.98 g/mol - Mass
(g) = 0.25 moles x 110.98 g/mol - Mass (g) = 27.745 g
Therefore, the mass in grams of 0.25 moles of calcium chloride
(CaCl2) is 27.745 grams.
Question 2
Step-by-step solution: 1. Determine the molar mass of NaCl: Na:
22.99 g/mol Cl: 35.45 g/mol Molar mass of NaCl = 22.99 g/mol +
35.45 g/mol = 58.44 g/mol
2. Calculate the number of moles of NaCl needed to prepare 500
mL of 0.25 M solution: 0.25 moles/L * 0.5 L = 0.125 moles
3. Convert moles to grams using the molar mass of NaCl: 0.125
moles * 58.44 g/mol = 7.305 g
Therefore, the student would need 7.305 grams of NaCl to prepare
500 mL of a 0.25 M solution.Question 2: A student wants to prepare
a solution of sodium chloride (NaCl) with a concentration of 0.25 M.
1
How many grams of NaCl would be needed to prepare 500 mL of this
solution?
Step-by-step solution: 1. Determine the molar mass of NaCl: Na:
22.99 g/mol Cl: 35.45 g/mol Molar mass of NaCl = 22.99 g/mol +
35.45 g/mol = 58.44 g/mol
2. Calculate the number of moles of NaCl needed to prepare 500
mL of 0.25 M solution: 0.25 moles/L * 0.5 L = 0.125 moles
3. Convert moles to grams using the molar mass of NaCl: 0.125
moles * 58.44 g/mol = 7.305 g
Therefore, the student would need 7.305 grams of NaCl to prepare
500 mL of a 0.25 M solution.
Question 3
Step-by-step solution: 1. Calculate the molar mass of sodium chlo-
ride (NaCl): - The molar mass of NaCl is the sum of the molar masses
of sodium (Na) and chlorine (Cl). - The molar mass of Na is approxi-
mately 22.99 g/mol, and the molar mass of Cl is approximately 35.45
g/mol. - Therefore, the molar mass of NaCl = 22.99 g/mol + 35.45
g/mol = 58.44 g/mol.
2. Determine the number of moles of NaCl: - Given mass of NaCl
= 25.0 grams - Number of moles = mass / molar mass - Number of
moles = 25.0 g / 58.44 g/mol 0.428 moles
3. Calculate the volume of the solution in liters: - Given volume
of solution = 500.0 mL = 500.0 cm
³
- Convert volume to liters: 500.0
cm
³
* (1 mL / 1 cm
³
) * (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity of the solution: - Molarity (M) = moles
of solute / volume of solution in liters - Molarity = 0.428 moles /
0.500 L 0.856 M
Therefore, the molarity of the solution containing 25.0 grams of
sodium chloride in 500.0 mL is approximately 0.856 M.Question 3:
Calculate the molarity of a solution that contains 25.0 grams of sodium
chloride (NaCl) dissolved in 500.0 mL of solution.
Step-by-step solution: 1. Calculate the molar mass of sodium chlo-
ride (NaCl): - The molar mass of NaCl is the sum of the molar masses
of sodium (Na) and chlorine (Cl). - The molar mass of Na is approxi-
mately 22.99 g/mol, and the molar mass of Cl is approximately 35.45
g/mol. - Therefore, the molar mass of NaCl = 22.99 g/mol + 35.45
g/mol = 58.44 g/mol.
2. Determine the number of moles of NaCl: - Given mass of NaCl
= 25.0 grams - Number of moles = mass / molar mass - Number of
moles = 25.0 g / 58.44 g/mol 0.428 moles
3. Calculate the volume of the solution in liters: - Given volume
of solution = 500.0 mL = 500.0 cm
³
- Convert volume to liters: 500.0
cm
³
* (1 mL / 1 cm
³
) * (1 L / 1000 mL) = 0.500 L
2
4. Calculate the molarity of the solution: - Molarity (M) = moles
of solute / volume of solution in liters - Molarity = 0.428 moles /
0.500 L 0.856 M
Therefore, the molarity of the solution containing 25.0 grams of
sodium chloride in 500.0 mL is approximately 0.856 M.
Question 4
Step-by-step solution: 1. Find the atomic mass of each element
present in sulfuric acid: - Hydrogen (H): Atomic mass = 1 g/mol -
Sulfur (S): Atomic mass = 32.06 g/mol - Oxygen (O): Atomic mass
= 16 g/mol
2. Determine the molecular formula of sulfuric acid, H2SO4. -
Multiply the atomic mass of hydrogen by 2: 2 * 1 g/mol = 2 g/mol
- Multiply the atomic mass of sulfur by 1: 1 * 32.06 g/mol = 32.06
g/mol - Multiply the atomic mass of oxygen by 4: 4 * 16 g/mol = 64
g/mol
3. Add the molar masses of each element to get the molar mass
of sulfuric acid: Molar mass of H2SO4 = 2 g/mol + 32.06 g/mol +
64 g/mol Molar mass of H2SO4 = 98.06 g/mol
Therefore, the molar mass of sulfuric acid, H2SO4, is 98.06 g/mol.Question
4: Calculate the molar mass of sulfuric acid, H2SO4.
Step-by-step solution: 1. Find the atomic mass of each element
present in sulfuric acid: - Hydrogen (H): Atomic mass = 1 g/mol -
Sulfur (S): Atomic mass = 32.06 g/mol - Oxygen (O): Atomic mass
= 16 g/mol
2. Determine the molecular formula of sulfuric acid, H2SO4. -
Multiply the atomic mass of hydrogen by 2: 2 * 1 g/mol = 2 g/mol
- Multiply the atomic mass of sulfur by 1: 1 * 32.06 g/mol = 32.06
g/mol - Multiply the atomic mass of oxygen by 4: 4 * 16 g/mol = 64
g/mol
3. Add the molar masses of each element to get the molar mass
of sulfuric acid: Molar mass of H2SO4 = 2 g/mol + 32.06 g/mol +
64 g/mol Molar mass of H2SO4 = 98.06 g/mol
Therefore, the molar mass of sulfuric acid, H2SO4, is 98.06 g/mol.
Question 5
Step-by-step solution: 1. Calculate the molar mass of KOH: - The
molar mass of potassium (K) = 39.10 g/mol - The molar mass of
oxygen (O) = 16.00 g/mol - The molar mass of hydrogen (H) = 1.01
g/mol - Molar mass of KOH = 39.10 + 16.00 + 1.01 = 56.11 g/mol
2. Calculate the number of moles of KOH: - Number of moles =
given mass / molar mass = 50.0 g / 56.11 g/mol 0.891 mol
3
3. Use the mole ratio from the balanced equation to find the
number of moles of KCl: - From the balanced equation, 2 moles of
KOH produce 1 mole of KCl. So, 0.891 mol KOH will produce 0.891
/ 2 = 0.4455 mol KCl
4. Calculate the molar mass of KCl: - The molar mass of potassium
(K) = 39.10 g/mol - The molar mass of chlorine (Cl) = 35.45 g/mol
- Molar mass of KCl = 39.10 + 35.45 = 74.55 g/mol
5. Calculate the mass of KCl produced: - Mass = number of moles
Ö
molar mass = 0.4455 mol
Ö
74.55 g/mol 33.27 g
Therefore, when 50.0 g of KOH reacts, approximately 33.27 g of
KCl is produced.Question 5: What mass of potassium chloride (KCl)
is produced when 50.0 g of potassium hydroxide (KOH) reacts with
excess hydrochloric acid (HCl) according to the following balanced
chemical equation? 2KOH + HCl
KCl + H2O
Step-by-step solution: 1. Calculate the molar mass of KOH: - The
molar mass of potassium (K) = 39.10 g/mol - The molar mass of
oxygen (O) = 16.00 g/mol - The molar mass of hydrogen (H) = 1.01
g/mol - Molar mass of KOH = 39.10 + 16.00 + 1.01 = 56.11 g/mol
2. Calculate the number of moles of KOH: - Number of moles =
given mass / molar mass = 50.0 g / 56.11 g/mol 0.891 mol
3. Use the mole ratio from the balanced equation to find the
number of moles of KCl: - From the balanced equation, 2 moles of
KOH produce 1 mole of KCl. So, 0.891 mol KOH will produce 0.891
/ 2 = 0.4455 mol KCl
4. Calculate the molar mass of KCl: - The molar mass of potassium
(K) = 39.10 g/mol - The molar mass of chlorine (Cl) = 35.45 g/mol
- Molar mass of KCl = 39.10 + 35.45 = 74.55 g/mol
5. Calculate the mass of KCl produced: - Mass = number of moles
Ö
molar mass = 0.4455 mol
Ö
74.55 g/mol 33.27 g
Therefore, when 50.0 g of KOH reacts, approximately 33.27 g of
KCl is produced.
Question 6
Step-by-step solution: 1. Calculate the molar mass of NaCl: Na:
1 atom x 22.99 g/mol = 22.99 g/mol Cl: 1 atom x 35.45 g/mol =
35.45 g/mol Molar mass of NaCl = 22.99 g/mol + 35.45 g/mol =
58.44 g/mol
2. Convert the mass of NaCl to moles: 25.0 g NaCl x (1 mol /
58.44 g) = 0.428 moles NaCl
3. Convert the volume of the solution to liters: 500.0 mL = 500.0
mL x (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity using the formula: Molarity (M) = moles
of solute / liters of solution Molarity = 0.428 moles / 0.500 L = 0.856
M
4
Therefore, the molarity of the solution is 0.856 M.Question 6: Cal-
culate the molarity of a solution that contains 25.0 grams of sodium
chloride (NaCl) dissolved in 500.0 mL of solution.
Step-by-step solution: 1. Calculate the molar mass of NaCl: Na:
1 atom x 22.99 g/mol = 22.99 g/mol Cl: 1 atom x 35.45 g/mol =
35.45 g/mol Molar mass of NaCl = 22.99 g/mol + 35.45 g/mol =
58.44 g/mol
2. Convert the mass of NaCl to moles: 25.0 g NaCl x (1 mol /
58.44 g) = 0.428 moles NaCl
3. Convert the volume of the solution to liters: 500.0 mL = 500.0
mL x (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity using the formula: Molarity (M) = moles
of solute / liters of solution Molarity = 0.428 moles / 0.500 L = 0.856
M
Therefore, the molarity of the solution is 0.856 M.
Question 7
Step 1: Determine the molar masses of each element present in
the compound. - Molar mass of potassium (K): 39.10 g/mol - Molar
mass of carbon (C): 12.01 g/mol - Molar mass of oxygen (O): 16.00
g/mol
Step 2: Calculate the molar mass of the entire compound by sum-
ming the molar masses of each element multiplied by their respective
subscripts in the chemical formula. Molar mass of K2CO3 = 2(K) +
1(C) + 3(O) Molar mass of K2CO3 = 2(39.10) + 12.01 + 3(16.00)
Molar mass of K2CO3 = 78.20 + 12.01 + 48.00 Molar mass of K2CO3
= 138.21 g/mol
Step 3: The molar mass of the compound K2CO3 is 138.21 g/mol.Question
7: What is the molar mass of a compound with the chemical formula
K2CO3?
Step 1: Determine the molar masses of each element present in
the compound. - Molar mass of potassium (K): 39.10 g/mol - Molar
mass of carbon (C): 12.01 g/mol - Molar mass of oxygen (O): 16.00
g/mol
Step 2: Calculate the molar mass of the entire compound by sum-
ming the molar masses of each element multiplied by their respective
subscripts in the chemical formula. Molar mass of K2CO3 = 2(K) +
1(C) + 3(O) Molar mass of K2CO3 = 2(39.10) + 12.01 + 3(16.00)
Molar mass of K2CO3 = 78.20 + 12.01 + 48.00 Molar mass of K2CO3
= 138.21 g/mol
Step 3: The molar mass of the compound K2CO3 is 138.21 g/mol.
5
Question 8
Step-by-step solution: 1. Calculate the molar mass of potassium
chloride (KCl): Molar mass of K = 39.10 g/mol Molar mass of Cl
= 35.45 g/mol Molar mass of KCl = 39.10 g/mol + 35.45 g/mol =
74.55 g/mol
2. Calculate the number of moles of potassium chloride in the
sample: Number of moles = Mass / Molar mass Number of moles =
25.0 g / 74.55 g/mol = 0.335 moles
3. Calculate the volume of the solution in liters: Volume = 500.0
mL = 500.0 mL * (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity of the solution: Molarity = Number of
moles / Volume of solution in liters Molarity = 0.335 moles / 0.500
L = 0.670 M
Therefore, the molarity of the resulting solution is 0.670 M.Question
8: A 25.0 g sample of potassium chloride (KCl) is dissolved in enough
water to make 500.0 mL of solution. Determine the molarity of the
resulting solution.
Step-by-step solution: 1. Calculate the molar mass of potassium
chloride (KCl): Molar mass of K = 39.10 g/mol Molar mass of Cl
= 35.45 g/mol Molar mass of KCl = 39.10 g/mol + 35.45 g/mol =
74.55 g/mol
2. Calculate the number of moles of potassium chloride in the
sample: Number of moles = Mass / Molar mass Number of moles =
25.0 g / 74.55 g/mol = 0.335 moles
3. Calculate the volume of the solution in liters: Volume = 500.0
mL = 500.0 mL * (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity of the solution: Molarity = Number of
moles / Volume of solution in liters Molarity = 0.335 moles / 0.500
L = 0.670 M
Therefore, the molarity of the resulting solution is 0.670 M.
Question 9
A sample of sodium chloride (NaCl) is dissolved in water to make
a 500 mL solution. The concentration of the solution is 0.2 M. What
is the mass of NaCl in the solution?
Step-by-step solution: 1. First, calculate the number of moles of
NaCl in the solution using the formula: Number of moles = con-
centration (M) x volume (L) Number of moles = 0.2 mol/L x 0.5 L
Number of moles = 0.1 mol
2. Next, use the molar mass of NaCl to convert moles to grams.
The molar mass of NaCl is 58.44 g/mol. Mass of NaCl = number of
moles x molar mass Mass of NaCl = 0.1 mol x 58.44 g/mol Mass of
NaCl = 5.844 g
6
Therefore, the mass of NaCl in the solution is 5.844 grams.Question
9:
A sample of sodium chloride (NaCl) is dissolved in water to make
a 500 mL solution. The concentration of the solution is 0.2 M. What
is the mass of NaCl in the solution?
Step-by-step solution: 1. First, calculate the number of moles of
NaCl in the solution using the formula: Number of moles = con-
centration (M) x volume (L) Number of moles = 0.2 mol/L x 0.5 L
Number of moles = 0.1 mol
2. Next, use the molar mass of NaCl to convert moles to grams.
The molar mass of NaCl is 58.44 g/mol. Mass of NaCl = number of
moles x molar mass Mass of NaCl = 0.1 mol x 58.44 g/mol Mass of
NaCl = 5.844 g
Therefore, the mass of NaCl in the solution is 5.844 grams.
Question 10
Step-by-step solution: 1. Calculate the molar mass of NaCl: -
Atomic mass of Na = 22.99 g/mol - Atomic mass of Cl = 35.45 g/mol
Molar mass of NaCl = 22.99 + 35.45 = 58.44 g/mol
2. Calculate the number of moles of NaCl in 25 grams: Number of
moles = Mass / Molar mass Number of moles = 25 g / 58.44 g/mol
0.428 moles
3. Convert the volume of the solution to liters: Volume = 500 mL
= 500 mL / 1000 mL/L = 0.5 L
4. Calculate the molarity of the solution: Molarity = Number of
moles / Volume of solution Molarity = 0.428 moles / 0.5 L = 0.856
M
Therefore, the molarity of the solution prepared by dissolving 25
grams of NaCl in enough water to make 500 mL of solution is 0.856
M.Question 10: Calculate the molarity of a solution prepared by
dissolving 25 grams of sodium chloride (NaCl) in enough water to
make 500 mL of solution.
Step-by-step solution: 1. Calculate the molar mass of NaCl: -
Atomic mass of Na = 22.99 g/mol - Atomic mass of Cl = 35.45 g/mol
Molar mass of NaCl = 22.99 + 35.45 = 58.44 g/mol
2. Calculate the number of moles of NaCl in 25 grams: Number of
moles = Mass / Molar mass Number of moles = 25 g / 58.44 g/mol
0.428 moles
3. Convert the volume of the solution to liters: Volume = 500 mL
= 500 mL / 1000 mL/L = 0.5 L
4. Calculate the molarity of the solution: Molarity = Number of
moles / Volume of solution Molarity = 0.428 moles / 0.5 L = 0.856
M
7
How many grams of NaCl would be needed to prepare 500 mL of this
solution?
Step-by-step solution: 1. Determine the molar mass of NaCl: Na:
22.99 g/mol Cl: 35.45 g/mol Molar mass of NaCl = 22.99 g/mol +
35.45 g/mol = 58.44 g/mol
2. Calculate the number of moles of NaCl needed to prepare 500
mL of 0.25 M solution: 0.25 moles/L * 0.5 L = 0.125 moles
3. Convert moles to grams using the molar mass of NaCl: 0.125
moles * 58.44 g/mol = 7.305 g
Therefore, the student would need 7.305 grams of NaCl to prepare
500 mL of a 0.25 M solution.
Question 3
Step-by-step solution: 1. Calculate the molar mass of sodium chlo-
ride (NaCl): - The molar mass of NaCl is the sum of the molar masses
of sodium (Na) and chlorine (Cl). - The molar mass of Na is approxi-
mately 22.99 g/mol, and the molar mass of Cl is approximately 35.45
g/mol. - Therefore, the molar mass of NaCl = 22.99 g/mol + 35.45
g/mol = 58.44 g/mol.
2. Determine the number of moles of NaCl: - Given mass of NaCl
= 25.0 grams - Number of moles = mass / molar mass - Number of
moles = 25.0 g / 58.44 g/mol 0.428 moles
3. Calculate the volume of the solution in liters: - Given volume
of solution = 500.0 mL = 500.0 cm
³
- Convert volume to liters: 500.0
cm
³
* (1 mL / 1 cm
³
) * (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity of the solution: - Molarity (M) = moles
of solute / volume of solution in liters - Molarity = 0.428 moles /
0.500 L 0.856 M
Therefore, the molarity of the solution containing 25.0 grams of
sodium chloride in 500.0 mL is approximately 0.856 M.Question 3:
Calculate the molarity of a solution that contains 25.0 grams of sodium
chloride (NaCl) dissolved in 500.0 mL of solution.
Step-by-step solution: 1. Calculate the molar mass of sodium chlo-
ride (NaCl): - The molar mass of NaCl is the sum of the molar masses
of sodium (Na) and chlorine (Cl). - The molar mass of Na is approxi-
mately 22.99 g/mol, and the molar mass of Cl is approximately 35.45
g/mol. - Therefore, the molar mass of NaCl = 22.99 g/mol + 35.45
g/mol = 58.44 g/mol.
2. Determine the number of moles of NaCl: - Given mass of NaCl
= 25.0 grams - Number of moles = mass / molar mass - Number of
moles = 25.0 g / 58.44 g/mol 0.428 moles
3. Calculate the volume of the solution in liters: - Given volume
of solution = 500.0 mL = 500.0 cm
³
- Convert volume to liters: 500.0
cm
³
* (1 mL / 1 cm
³
) * (1 L / 1000 mL) = 0.500 L
2
4. Calculate the molarity of the solution: - Molarity (M) = moles
of solute / volume of solution in liters - Molarity = 0.428 moles /
0.500 L 0.856 M
Therefore, the molarity of the solution containing 25.0 grams of
sodium chloride in 500.0 mL is approximately 0.856 M.
Question 4
Step-by-step solution: 1. Find the atomic mass of each element
present in sulfuric acid: - Hydrogen (H): Atomic mass = 1 g/mol -
Sulfur (S): Atomic mass = 32.06 g/mol - Oxygen (O): Atomic mass
= 16 g/mol
2. Determine the molecular formula of sulfuric acid, H2SO4. -
Multiply the atomic mass of hydrogen by 2: 2 * 1 g/mol = 2 g/mol
- Multiply the atomic mass of sulfur by 1: 1 * 32.06 g/mol = 32.06
g/mol - Multiply the atomic mass of oxygen by 4: 4 * 16 g/mol = 64
g/mol
3. Add the molar masses of each element to get the molar mass
of sulfuric acid: Molar mass of H2SO4 = 2 g/mol + 32.06 g/mol +
64 g/mol Molar mass of H2SO4 = 98.06 g/mol
Therefore, the molar mass of sulfuric acid, H2SO4, is 98.06 g/mol.Question
4: Calculate the molar mass of sulfuric acid, H2SO4.
Step-by-step solution: 1. Find the atomic mass of each element
present in sulfuric acid: - Hydrogen (H): Atomic mass = 1 g/mol -
Sulfur (S): Atomic mass = 32.06 g/mol - Oxygen (O): Atomic mass
= 16 g/mol
2. Determine the molecular formula of sulfuric acid, H2SO4. -
Multiply the atomic mass of hydrogen by 2: 2 * 1 g/mol = 2 g/mol
- Multiply the atomic mass of sulfur by 1: 1 * 32.06 g/mol = 32.06
g/mol - Multiply the atomic mass of oxygen by 4: 4 * 16 g/mol = 64
g/mol
3. Add the molar masses of each element to get the molar mass
of sulfuric acid: Molar mass of H2SO4 = 2 g/mol + 32.06 g/mol +
64 g/mol Molar mass of H2SO4 = 98.06 g/mol
Therefore, the molar mass of sulfuric acid, H2SO4, is 98.06 g/mol.
Question 5
Step-by-step solution: 1. Calculate the molar mass of KOH: - The
molar mass of potassium (K) = 39.10 g/mol - The molar mass of
oxygen (O) = 16.00 g/mol - The molar mass of hydrogen (H) = 1.01
g/mol - Molar mass of KOH = 39.10 + 16.00 + 1.01 = 56.11 g/mol
2. Calculate the number of moles of KOH: - Number of moles =
given mass / molar mass = 50.0 g / 56.11 g/mol 0.891 mol
3
3. Use the mole ratio from the balanced equation to find the
number of moles of KCl: - From the balanced equation, 2 moles of
KOH produce 1 mole of KCl. So, 0.891 mol KOH will produce 0.891
/ 2 = 0.4455 mol KCl
4. Calculate the molar mass of KCl: - The molar mass of potassium
(K) = 39.10 g/mol - The molar mass of chlorine (Cl) = 35.45 g/mol
- Molar mass of KCl = 39.10 + 35.45 = 74.55 g/mol
5. Calculate the mass of KCl produced: - Mass = number of moles
Ö
molar mass = 0.4455 mol
Ö
74.55 g/mol 33.27 g
Therefore, when 50.0 g of KOH reacts, approximately 33.27 g of
KCl is produced.Question 5: What mass of potassium chloride (KCl)
is produced when 50.0 g of potassium hydroxide (KOH) reacts with
excess hydrochloric acid (HCl) according to the following balanced
chemical equation? 2KOH + HCl
KCl + H2O
Step-by-step solution: 1. Calculate the molar mass of KOH: - The
molar mass of potassium (K) = 39.10 g/mol - The molar mass of
oxygen (O) = 16.00 g/mol - The molar mass of hydrogen (H) = 1.01
g/mol - Molar mass of KOH = 39.10 + 16.00 + 1.01 = 56.11 g/mol
2. Calculate the number of moles of KOH: - Number of moles =
given mass / molar mass = 50.0 g / 56.11 g/mol 0.891 mol
3. Use the mole ratio from the balanced equation to find the
number of moles of KCl: - From the balanced equation, 2 moles of
KOH produce 1 mole of KCl. So, 0.891 mol KOH will produce 0.891
/ 2 = 0.4455 mol KCl
4. Calculate the molar mass of KCl: - The molar mass of potassium
(K) = 39.10 g/mol - The molar mass of chlorine (Cl) = 35.45 g/mol
- Molar mass of KCl = 39.10 + 35.45 = 74.55 g/mol
5. Calculate the mass of KCl produced: - Mass = number of moles
Ö
molar mass = 0.4455 mol
Ö
74.55 g/mol 33.27 g
Therefore, when 50.0 g of KOH reacts, approximately 33.27 g of
KCl is produced.
Question 6
Step-by-step solution: 1. Calculate the molar mass of NaCl: Na:
1 atom x 22.99 g/mol = 22.99 g/mol Cl: 1 atom x 35.45 g/mol =
35.45 g/mol Molar mass of NaCl = 22.99 g/mol + 35.45 g/mol =
58.44 g/mol
2. Convert the mass of NaCl to moles: 25.0 g NaCl x (1 mol /
58.44 g) = 0.428 moles NaCl
3. Convert the volume of the solution to liters: 500.0 mL = 500.0
mL x (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity using the formula: Molarity (M) = moles
of solute / liters of solution Molarity = 0.428 moles / 0.500 L = 0.856
M
4
Therefore, the molarity of the solution is 0.856 M.Question 6: Cal-
culate the molarity of a solution that contains 25.0 grams of sodium
chloride (NaCl) dissolved in 500.0 mL of solution.
Step-by-step solution: 1. Calculate the molar mass of NaCl: Na:
1 atom x 22.99 g/mol = 22.99 g/mol Cl: 1 atom x 35.45 g/mol =
35.45 g/mol Molar mass of NaCl = 22.99 g/mol + 35.45 g/mol =
58.44 g/mol
2. Convert the mass of NaCl to moles: 25.0 g NaCl x (1 mol /
58.44 g) = 0.428 moles NaCl
3. Convert the volume of the solution to liters: 500.0 mL = 500.0
mL x (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity using the formula: Molarity (M) = moles
of solute / liters of solution Molarity = 0.428 moles / 0.500 L = 0.856
M
Therefore, the molarity of the solution is 0.856 M.
Question 7
Step 1: Determine the molar masses of each element present in
the compound. - Molar mass of potassium (K): 39.10 g/mol - Molar
mass of carbon (C): 12.01 g/mol - Molar mass of oxygen (O): 16.00
g/mol
Step 2: Calculate the molar mass of the entire compound by sum-
ming the molar masses of each element multiplied by their respective
subscripts in the chemical formula. Molar mass of K2CO3 = 2(K) +
1(C) + 3(O) Molar mass of K2CO3 = 2(39.10) + 12.01 + 3(16.00)
Molar mass of K2CO3 = 78.20 + 12.01 + 48.00 Molar mass of K2CO3
= 138.21 g/mol
Step 3: The molar mass of the compound K2CO3 is 138.21 g/mol.Question
7: What is the molar mass of a compound with the chemical formula
K2CO3?
Step 1: Determine the molar masses of each element present in
the compound. - Molar mass of potassium (K): 39.10 g/mol - Molar
mass of carbon (C): 12.01 g/mol - Molar mass of oxygen (O): 16.00
g/mol
Step 2: Calculate the molar mass of the entire compound by sum-
ming the molar masses of each element multiplied by their respective
subscripts in the chemical formula. Molar mass of K2CO3 = 2(K) +
1(C) + 3(O) Molar mass of K2CO3 = 2(39.10) + 12.01 + 3(16.00)
Molar mass of K2CO3 = 78.20 + 12.01 + 48.00 Molar mass of K2CO3
= 138.21 g/mol
Step 3: The molar mass of the compound K2CO3 is 138.21 g/mol.
5
Question 8
Step-by-step solution: 1. Calculate the molar mass of potassium
chloride (KCl): Molar mass of K = 39.10 g/mol Molar mass of Cl
= 35.45 g/mol Molar mass of KCl = 39.10 g/mol + 35.45 g/mol =
74.55 g/mol
2. Calculate the number of moles of potassium chloride in the
sample: Number of moles = Mass / Molar mass Number of moles =
25.0 g / 74.55 g/mol = 0.335 moles
3. Calculate the volume of the solution in liters: Volume = 500.0
mL = 500.0 mL * (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity of the solution: Molarity = Number of
moles / Volume of solution in liters Molarity = 0.335 moles / 0.500
L = 0.670 M
Therefore, the molarity of the resulting solution is 0.670 M.Question
8: A 25.0 g sample of potassium chloride (KCl) is dissolved in enough
water to make 500.0 mL of solution. Determine the molarity of the
resulting solution.
Step-by-step solution: 1. Calculate the molar mass of potassium
chloride (KCl): Molar mass of K = 39.10 g/mol Molar mass of Cl
= 35.45 g/mol Molar mass of KCl = 39.10 g/mol + 35.45 g/mol =
74.55 g/mol
2. Calculate the number of moles of potassium chloride in the
sample: Number of moles = Mass / Molar mass Number of moles =
25.0 g / 74.55 g/mol = 0.335 moles
3. Calculate the volume of the solution in liters: Volume = 500.0
mL = 500.0 mL * (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity of the solution: Molarity = Number of
moles / Volume of solution in liters Molarity = 0.335 moles / 0.500
L = 0.670 M
Therefore, the molarity of the resulting solution is 0.670 M.
Question 9
A sample of sodium chloride (NaCl) is dissolved in water to make
a 500 mL solution. The concentration of the solution is 0.2 M. What
is the mass of NaCl in the solution?
Step-by-step solution: 1. First, calculate the number of moles of
NaCl in the solution using the formula: Number of moles = con-
centration (M) x volume (L) Number of moles = 0.2 mol/L x 0.5 L
Number of moles = 0.1 mol
2. Next, use the molar mass of NaCl to convert moles to grams.
The molar mass of NaCl is 58.44 g/mol. Mass of NaCl = number of
moles x molar mass Mass of NaCl = 0.1 mol x 58.44 g/mol Mass of
NaCl = 5.844 g
6
Therefore, the mass of NaCl in the solution is 5.844 grams.Question
9:
A sample of sodium chloride (NaCl) is dissolved in water to make
a 500 mL solution. The concentration of the solution is 0.2 M. What
is the mass of NaCl in the solution?
Step-by-step solution: 1. First, calculate the number of moles of
NaCl in the solution using the formula: Number of moles = con-
centration (M) x volume (L) Number of moles = 0.2 mol/L x 0.5 L
Number of moles = 0.1 mol
2. Next, use the molar mass of NaCl to convert moles to grams.
The molar mass of NaCl is 58.44 g/mol. Mass of NaCl = number of
moles x molar mass Mass of NaCl = 0.1 mol x 58.44 g/mol Mass of
NaCl = 5.844 g
Therefore, the mass of NaCl in the solution is 5.844 grams.
Question 10
Step-by-step solution: 1. Calculate the molar mass of NaCl: -
Atomic mass of Na = 22.99 g/mol - Atomic mass of Cl = 35.45 g/mol
Molar mass of NaCl = 22.99 + 35.45 = 58.44 g/mol
2. Calculate the number of moles of NaCl in 25 grams: Number of
moles = Mass / Molar mass Number of moles = 25 g / 58.44 g/mol
0.428 moles
3. Convert the volume of the solution to liters: Volume = 500 mL
= 500 mL / 1000 mL/L = 0.5 L
4. Calculate the molarity of the solution: Molarity = Number of
moles / Volume of solution Molarity = 0.428 moles / 0.5 L = 0.856
M
Therefore, the molarity of the solution prepared by dissolving 25
grams of NaCl in enough water to make 500 mL of solution is 0.856
M.Question 10: Calculate the molarity of a solution prepared by
dissolving 25 grams of sodium chloride (NaCl) in enough water to
make 500 mL of solution.
Step-by-step solution: 1. Calculate the molar mass of NaCl: -
Atomic mass of Na = 22.99 g/mol - Atomic mass of Cl = 35.45 g/mol
Molar mass of NaCl = 22.99 + 35.45 = 58.44 g/mol
2. Calculate the number of moles of NaCl in 25 grams: Number of
moles = Mass / Molar mass Number of moles = 25 g / 58.44 g/mol
0.428 moles
3. Convert the volume of the solution to liters: Volume = 500 mL
= 500 mL / 1000 mL/L = 0.5 L
4. Calculate the molarity of the solution: Molarity = Number of
moles / Volume of solution Molarity = 0.428 moles / 0.5 L = 0.856
M
7
How many grams of NaCl would be needed to prepare 500 mL of this
solution?
Step-by-step solution: 1. Determine the molar mass of NaCl: Na:
22.99 g/mol Cl: 35.45 g/mol Molar mass of NaCl = 22.99 g/mol +
35.45 g/mol = 58.44 g/mol
2. Calculate the number of moles of NaCl needed to prepare 500
mL of 0.25 M solution: 0.25 moles/L * 0.5 L = 0.125 moles
3. Convert moles to grams using the molar mass of NaCl: 0.125
moles * 58.44 g/mol = 7.305 g
Therefore, the student would need 7.305 grams of NaCl to prepare
500 mL of a 0.25 M solution.
Question 3
Step-by-step solution: 1. Calculate the molar mass of sodium chlo-
ride (NaCl): - The molar mass of NaCl is the sum of the molar masses
of sodium (Na) and chlorine (Cl). - The molar mass of Na is approxi-
mately 22.99 g/mol, and the molar mass of Cl is approximately 35.45
g/mol. - Therefore, the molar mass of NaCl = 22.99 g/mol + 35.45
g/mol = 58.44 g/mol.
2. Determine the number of moles of NaCl: - Given mass of NaCl
= 25.0 grams - Number of moles = mass / molar mass - Number of
moles = 25.0 g / 58.44 g/mol 0.428 moles
3. Calculate the volume of the solution in liters: - Given volume
of solution = 500.0 mL = 500.0 cm
³
- Convert volume to liters: 500.0
cm
³
* (1 mL / 1 cm
³
) * (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity of the solution: - Molarity (M) = moles
of solute / volume of solution in liters - Molarity = 0.428 moles /
0.500 L 0.856 M
Therefore, the molarity of the solution containing 25.0 grams of
sodium chloride in 500.0 mL is approximately 0.856 M.Question 3:
Calculate the molarity of a solution that contains 25.0 grams of sodium
chloride (NaCl) dissolved in 500.0 mL of solution.
Step-by-step solution: 1. Calculate the molar mass of sodium chlo-
ride (NaCl): - The molar mass of NaCl is the sum of the molar masses
of sodium (Na) and chlorine (Cl). - The molar mass of Na is approxi-
mately 22.99 g/mol, and the molar mass of Cl is approximately 35.45
g/mol. - Therefore, the molar mass of NaCl = 22.99 g/mol + 35.45
g/mol = 58.44 g/mol.
2. Determine the number of moles of NaCl: - Given mass of NaCl
= 25.0 grams - Number of moles = mass / molar mass - Number of
moles = 25.0 g / 58.44 g/mol 0.428 moles
3. Calculate the volume of the solution in liters: - Given volume
of solution = 500.0 mL = 500.0 cm
³
- Convert volume to liters: 500.0
cm
³
* (1 mL / 1 cm
³
) * (1 L / 1000 mL) = 0.500 L
2
4. Calculate the molarity of the solution: - Molarity (M) = moles
of solute / volume of solution in liters - Molarity = 0.428 moles /
0.500 L 0.856 M
Therefore, the molarity of the solution containing 25.0 grams of
sodium chloride in 500.0 mL is approximately 0.856 M.
Question 4
Step-by-step solution: 1. Find the atomic mass of each element
present in sulfuric acid: - Hydrogen (H): Atomic mass = 1 g/mol -
Sulfur (S): Atomic mass = 32.06 g/mol - Oxygen (O): Atomic mass
= 16 g/mol
2. Determine the molecular formula of sulfuric acid, H2SO4. -
Multiply the atomic mass of hydrogen by 2: 2 * 1 g/mol = 2 g/mol
- Multiply the atomic mass of sulfur by 1: 1 * 32.06 g/mol = 32.06
g/mol - Multiply the atomic mass of oxygen by 4: 4 * 16 g/mol = 64
g/mol
3. Add the molar masses of each element to get the molar mass
of sulfuric acid: Molar mass of H2SO4 = 2 g/mol + 32.06 g/mol +
64 g/mol Molar mass of H2SO4 = 98.06 g/mol
Therefore, the molar mass of sulfuric acid, H2SO4, is 98.06 g/mol.Question
4: Calculate the molar mass of sulfuric acid, H2SO4.
Step-by-step solution: 1. Find the atomic mass of each element
present in sulfuric acid: - Hydrogen (H): Atomic mass = 1 g/mol -
Sulfur (S): Atomic mass = 32.06 g/mol - Oxygen (O): Atomic mass
= 16 g/mol
2. Determine the molecular formula of sulfuric acid, H2SO4. -
Multiply the atomic mass of hydrogen by 2: 2 * 1 g/mol = 2 g/mol
- Multiply the atomic mass of sulfur by 1: 1 * 32.06 g/mol = 32.06
g/mol - Multiply the atomic mass of oxygen by 4: 4 * 16 g/mol = 64
g/mol
3. Add the molar masses of each element to get the molar mass
of sulfuric acid: Molar mass of H2SO4 = 2 g/mol + 32.06 g/mol +
64 g/mol Molar mass of H2SO4 = 98.06 g/mol
Therefore, the molar mass of sulfuric acid, H2SO4, is 98.06 g/mol.
Question 5
Step-by-step solution: 1. Calculate the molar mass of KOH: - The
molar mass of potassium (K) = 39.10 g/mol - The molar mass of
oxygen (O) = 16.00 g/mol - The molar mass of hydrogen (H) = 1.01
g/mol - Molar mass of KOH = 39.10 + 16.00 + 1.01 = 56.11 g/mol
2. Calculate the number of moles of KOH: - Number of moles =
given mass / molar mass = 50.0 g / 56.11 g/mol 0.891 mol
3
3. Use the mole ratio from the balanced equation to find the
number of moles of KCl: - From the balanced equation, 2 moles of
KOH produce 1 mole of KCl. So, 0.891 mol KOH will produce 0.891
/ 2 = 0.4455 mol KCl
4. Calculate the molar mass of KCl: - The molar mass of potassium
(K) = 39.10 g/mol - The molar mass of chlorine (Cl) = 35.45 g/mol
- Molar mass of KCl = 39.10 + 35.45 = 74.55 g/mol
5. Calculate the mass of KCl produced: - Mass = number of moles
Ö
molar mass = 0.4455 mol
Ö
74.55 g/mol 33.27 g
Therefore, when 50.0 g of KOH reacts, approximately 33.27 g of
KCl is produced.Question 5: What mass of potassium chloride (KCl)
is produced when 50.0 g of potassium hydroxide (KOH) reacts with
excess hydrochloric acid (HCl) according to the following balanced
chemical equation? 2KOH + HCl
KCl + H2O
Step-by-step solution: 1. Calculate the molar mass of KOH: - The
molar mass of potassium (K) = 39.10 g/mol - The molar mass of
oxygen (O) = 16.00 g/mol - The molar mass of hydrogen (H) = 1.01
g/mol - Molar mass of KOH = 39.10 + 16.00 + 1.01 = 56.11 g/mol
2. Calculate the number of moles of KOH: - Number of moles =
given mass / molar mass = 50.0 g / 56.11 g/mol 0.891 mol
3. Use the mole ratio from the balanced equation to find the
number of moles of KCl: - From the balanced equation, 2 moles of
KOH produce 1 mole of KCl. So, 0.891 mol KOH will produce 0.891
/ 2 = 0.4455 mol KCl
4. Calculate the molar mass of KCl: - The molar mass of potassium
(K) = 39.10 g/mol - The molar mass of chlorine (Cl) = 35.45 g/mol
- Molar mass of KCl = 39.10 + 35.45 = 74.55 g/mol
5. Calculate the mass of KCl produced: - Mass = number of moles
Ö
molar mass = 0.4455 mol
Ö
74.55 g/mol 33.27 g
Therefore, when 50.0 g of KOH reacts, approximately 33.27 g of
KCl is produced.
Question 6
Step-by-step solution: 1. Calculate the molar mass of NaCl: Na:
1 atom x 22.99 g/mol = 22.99 g/mol Cl: 1 atom x 35.45 g/mol =
35.45 g/mol Molar mass of NaCl = 22.99 g/mol + 35.45 g/mol =
58.44 g/mol
2. Convert the mass of NaCl to moles: 25.0 g NaCl x (1 mol /
58.44 g) = 0.428 moles NaCl
3. Convert the volume of the solution to liters: 500.0 mL = 500.0
mL x (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity using the formula: Molarity (M) = moles
of solute / liters of solution Molarity = 0.428 moles / 0.500 L = 0.856
M
4
Therefore, the molarity of the solution is 0.856 M.Question 6: Cal-
culate the molarity of a solution that contains 25.0 grams of sodium
chloride (NaCl) dissolved in 500.0 mL of solution.
Step-by-step solution: 1. Calculate the molar mass of NaCl: Na:
1 atom x 22.99 g/mol = 22.99 g/mol Cl: 1 atom x 35.45 g/mol =
35.45 g/mol Molar mass of NaCl = 22.99 g/mol + 35.45 g/mol =
58.44 g/mol
2. Convert the mass of NaCl to moles: 25.0 g NaCl x (1 mol /
58.44 g) = 0.428 moles NaCl
3. Convert the volume of the solution to liters: 500.0 mL = 500.0
mL x (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity using the formula: Molarity (M) = moles
of solute / liters of solution Molarity = 0.428 moles / 0.500 L = 0.856
M
Therefore, the molarity of the solution is 0.856 M.
Question 7
Step 1: Determine the molar masses of each element present in
the compound. - Molar mass of potassium (K): 39.10 g/mol - Molar
mass of carbon (C): 12.01 g/mol - Molar mass of oxygen (O): 16.00
g/mol
Step 2: Calculate the molar mass of the entire compound by sum-
ming the molar masses of each element multiplied by their respective
subscripts in the chemical formula. Molar mass of K2CO3 = 2(K) +
1(C) + 3(O) Molar mass of K2CO3 = 2(39.10) + 12.01 + 3(16.00)
Molar mass of K2CO3 = 78.20 + 12.01 + 48.00 Molar mass of K2CO3
= 138.21 g/mol
Step 3: The molar mass of the compound K2CO3 is 138.21 g/mol.Question
7: What is the molar mass of a compound with the chemical formula
K2CO3?
Step 1: Determine the molar masses of each element present in
the compound. - Molar mass of potassium (K): 39.10 g/mol - Molar
mass of carbon (C): 12.01 g/mol - Molar mass of oxygen (O): 16.00
g/mol
Step 2: Calculate the molar mass of the entire compound by sum-
ming the molar masses of each element multiplied by their respective
subscripts in the chemical formula. Molar mass of K2CO3 = 2(K) +
1(C) + 3(O) Molar mass of K2CO3 = 2(39.10) + 12.01 + 3(16.00)
Molar mass of K2CO3 = 78.20 + 12.01 + 48.00 Molar mass of K2CO3
= 138.21 g/mol
Step 3: The molar mass of the compound K2CO3 is 138.21 g/mol.
5
Question 8
Step-by-step solution: 1. Calculate the molar mass of potassium
chloride (KCl): Molar mass of K = 39.10 g/mol Molar mass of Cl
= 35.45 g/mol Molar mass of KCl = 39.10 g/mol + 35.45 g/mol =
74.55 g/mol
2. Calculate the number of moles of potassium chloride in the
sample: Number of moles = Mass / Molar mass Number of moles =
25.0 g / 74.55 g/mol = 0.335 moles
3. Calculate the volume of the solution in liters: Volume = 500.0
mL = 500.0 mL * (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity of the solution: Molarity = Number of
moles / Volume of solution in liters Molarity = 0.335 moles / 0.500
L = 0.670 M
Therefore, the molarity of the resulting solution is 0.670 M.Question
8: A 25.0 g sample of potassium chloride (KCl) is dissolved in enough
water to make 500.0 mL of solution. Determine the molarity of the
resulting solution.
Step-by-step solution: 1. Calculate the molar mass of potassium
chloride (KCl): Molar mass of K = 39.10 g/mol Molar mass of Cl
= 35.45 g/mol Molar mass of KCl = 39.10 g/mol + 35.45 g/mol =
74.55 g/mol
2. Calculate the number of moles of potassium chloride in the
sample: Number of moles = Mass / Molar mass Number of moles =
25.0 g / 74.55 g/mol = 0.335 moles
3. Calculate the volume of the solution in liters: Volume = 500.0
mL = 500.0 mL * (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity of the solution: Molarity = Number of
moles / Volume of solution in liters Molarity = 0.335 moles / 0.500
L = 0.670 M
Therefore, the molarity of the resulting solution is 0.670 M.
Question 9
A sample of sodium chloride (NaCl) is dissolved in water to make
a 500 mL solution. The concentration of the solution is 0.2 M. What
is the mass of NaCl in the solution?
Step-by-step solution: 1. First, calculate the number of moles of
NaCl in the solution using the formula: Number of moles = con-
centration (M) x volume (L) Number of moles = 0.2 mol/L x 0.5 L
Number of moles = 0.1 mol
2. Next, use the molar mass of NaCl to convert moles to grams.
The molar mass of NaCl is 58.44 g/mol. Mass of NaCl = number of
moles x molar mass Mass of NaCl = 0.1 mol x 58.44 g/mol Mass of
NaCl = 5.844 g
6
Therefore, the mass of NaCl in the solution is 5.844 grams.Question
9:
A sample of sodium chloride (NaCl) is dissolved in water to make
a 500 mL solution. The concentration of the solution is 0.2 M. What
is the mass of NaCl in the solution?
Step-by-step solution: 1. First, calculate the number of moles of
NaCl in the solution using the formula: Number of moles = con-
centration (M) x volume (L) Number of moles = 0.2 mol/L x 0.5 L
Number of moles = 0.1 mol
2. Next, use the molar mass of NaCl to convert moles to grams.
The molar mass of NaCl is 58.44 g/mol. Mass of NaCl = number of
moles x molar mass Mass of NaCl = 0.1 mol x 58.44 g/mol Mass of
NaCl = 5.844 g
Therefore, the mass of NaCl in the solution is 5.844 grams.
Question 10
Step-by-step solution: 1. Calculate the molar mass of NaCl: -
Atomic mass of Na = 22.99 g/mol - Atomic mass of Cl = 35.45 g/mol
Molar mass of NaCl = 22.99 + 35.45 = 58.44 g/mol
2. Calculate the number of moles of NaCl in 25 grams: Number of
moles = Mass / Molar mass Number of moles = 25 g / 58.44 g/mol
0.428 moles
3. Convert the volume of the solution to liters: Volume = 500 mL
= 500 mL / 1000 mL/L = 0.5 L
4. Calculate the molarity of the solution: Molarity = Number of
moles / Volume of solution Molarity = 0.428 moles / 0.5 L = 0.856
M
Therefore, the molarity of the solution prepared by dissolving 25
grams of NaCl in enough water to make 500 mL of solution is 0.856
M.Question 10: Calculate the molarity of a solution prepared by
dissolving 25 grams of sodium chloride (NaCl) in enough water to
make 500 mL of solution.
Step-by-step solution: 1. Calculate the molar mass of NaCl: -
Atomic mass of Na = 22.99 g/mol - Atomic mass of Cl = 35.45 g/mol
Molar mass of NaCl = 22.99 + 35.45 = 58.44 g/mol
2. Calculate the number of moles of NaCl in 25 grams: Number of
moles = Mass / Molar mass Number of moles = 25 g / 58.44 g/mol
0.428 moles
3. Convert the volume of the solution to liters: Volume = 500 mL
= 500 mL / 1000 mL/L = 0.5 L
4. Calculate the molarity of the solution: Molarity = Number of
moles / Volume of solution Molarity = 0.428 moles / 0.5 L = 0.856
M
7
How many grams of NaCl would be needed to prepare 500 mL of this
solution?
Step-by-step solution: 1. Determine the molar mass of NaCl: Na:
22.99 g/mol Cl: 35.45 g/mol Molar mass of NaCl = 22.99 g/mol +
35.45 g/mol = 58.44 g/mol
2. Calculate the number of moles of NaCl needed to prepare 500
mL of 0.25 M solution: 0.25 moles/L * 0.5 L = 0.125 moles
3. Convert moles to grams using the molar mass of NaCl: 0.125
moles * 58.44 g/mol = 7.305 g
Therefore, the student would need 7.305 grams of NaCl to prepare
500 mL of a 0.25 M solution.
Question 3
Step-by-step solution: 1. Calculate the molar mass of sodium chlo-
ride (NaCl): - The molar mass of NaCl is the sum of the molar masses
of sodium (Na) and chlorine (Cl). - The molar mass of Na is approxi-
mately 22.99 g/mol, and the molar mass of Cl is approximately 35.45
g/mol. - Therefore, the molar mass of NaCl = 22.99 g/mol + 35.45
g/mol = 58.44 g/mol.
2. Determine the number of moles of NaCl: - Given mass of NaCl
= 25.0 grams - Number of moles = mass / molar mass - Number of
moles = 25.0 g / 58.44 g/mol 0.428 moles
3. Calculate the volume of the solution in liters: - Given volume
of solution = 500.0 mL = 500.0 cm
³
- Convert volume to liters: 500.0
cm
³
* (1 mL / 1 cm
³
) * (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity of the solution: - Molarity (M) = moles
of solute / volume of solution in liters - Molarity = 0.428 moles /
0.500 L 0.856 M
Therefore, the molarity of the solution containing 25.0 grams of
sodium chloride in 500.0 mL is approximately 0.856 M.Question 3:
Calculate the molarity of a solution that contains 25.0 grams of sodium
chloride (NaCl) dissolved in 500.0 mL of solution.
Step-by-step solution: 1. Calculate the molar mass of sodium chlo-
ride (NaCl): - The molar mass of NaCl is the sum of the molar masses
of sodium (Na) and chlorine (Cl). - The molar mass of Na is approxi-
mately 22.99 g/mol, and the molar mass of Cl is approximately 35.45
g/mol. - Therefore, the molar mass of NaCl = 22.99 g/mol + 35.45
g/mol = 58.44 g/mol.
2. Determine the number of moles of NaCl: - Given mass of NaCl
= 25.0 grams - Number of moles = mass / molar mass - Number of
moles = 25.0 g / 58.44 g/mol 0.428 moles
3. Calculate the volume of the solution in liters: - Given volume
of solution = 500.0 mL = 500.0 cm
³
- Convert volume to liters: 500.0
cm
³
* (1 mL / 1 cm
³
) * (1 L / 1000 mL) = 0.500 L
2
4. Calculate the molarity of the solution: - Molarity (M) = moles
of solute / volume of solution in liters - Molarity = 0.428 moles /
0.500 L 0.856 M
Therefore, the molarity of the solution containing 25.0 grams of
sodium chloride in 500.0 mL is approximately 0.856 M.
Question 4
Step-by-step solution: 1. Find the atomic mass of each element
present in sulfuric acid: - Hydrogen (H): Atomic mass = 1 g/mol -
Sulfur (S): Atomic mass = 32.06 g/mol - Oxygen (O): Atomic mass
= 16 g/mol
2. Determine the molecular formula of sulfuric acid, H2SO4. -
Multiply the atomic mass of hydrogen by 2: 2 * 1 g/mol = 2 g/mol
- Multiply the atomic mass of sulfur by 1: 1 * 32.06 g/mol = 32.06
g/mol - Multiply the atomic mass of oxygen by 4: 4 * 16 g/mol = 64
g/mol
3. Add the molar masses of each element to get the molar mass
of sulfuric acid: Molar mass of H2SO4 = 2 g/mol + 32.06 g/mol +
64 g/mol Molar mass of H2SO4 = 98.06 g/mol
Therefore, the molar mass of sulfuric acid, H2SO4, is 98.06 g/mol.Question
4: Calculate the molar mass of sulfuric acid, H2SO4.
Step-by-step solution: 1. Find the atomic mass of each element
present in sulfuric acid: - Hydrogen (H): Atomic mass = 1 g/mol -
Sulfur (S): Atomic mass = 32.06 g/mol - Oxygen (O): Atomic mass
= 16 g/mol
2. Determine the molecular formula of sulfuric acid, H2SO4. -
Multiply the atomic mass of hydrogen by 2: 2 * 1 g/mol = 2 g/mol
- Multiply the atomic mass of sulfur by 1: 1 * 32.06 g/mol = 32.06
g/mol - Multiply the atomic mass of oxygen by 4: 4 * 16 g/mol = 64
g/mol
3. Add the molar masses of each element to get the molar mass
of sulfuric acid: Molar mass of H2SO4 = 2 g/mol + 32.06 g/mol +
64 g/mol Molar mass of H2SO4 = 98.06 g/mol
Therefore, the molar mass of sulfuric acid, H2SO4, is 98.06 g/mol.
Question 5
Step-by-step solution: 1. Calculate the molar mass of KOH: - The
molar mass of potassium (K) = 39.10 g/mol - The molar mass of
oxygen (O) = 16.00 g/mol - The molar mass of hydrogen (H) = 1.01
g/mol - Molar mass of KOH = 39.10 + 16.00 + 1.01 = 56.11 g/mol
2. Calculate the number of moles of KOH: - Number of moles =
given mass / molar mass = 50.0 g / 56.11 g/mol 0.891 mol
3
3. Use the mole ratio from the balanced equation to find the
number of moles of KCl: - From the balanced equation, 2 moles of
KOH produce 1 mole of KCl. So, 0.891 mol KOH will produce 0.891
/ 2 = 0.4455 mol KCl
4. Calculate the molar mass of KCl: - The molar mass of potassium
(K) = 39.10 g/mol - The molar mass of chlorine (Cl) = 35.45 g/mol
- Molar mass of KCl = 39.10 + 35.45 = 74.55 g/mol
5. Calculate the mass of KCl produced: - Mass = number of moles
Ö
molar mass = 0.4455 mol
Ö
74.55 g/mol 33.27 g
Therefore, when 50.0 g of KOH reacts, approximately 33.27 g of
KCl is produced.Question 5: What mass of potassium chloride (KCl)
is produced when 50.0 g of potassium hydroxide (KOH) reacts with
excess hydrochloric acid (HCl) according to the following balanced
chemical equation? 2KOH + HCl
KCl + H2O
Step-by-step solution: 1. Calculate the molar mass of KOH: - The
molar mass of potassium (K) = 39.10 g/mol - The molar mass of
oxygen (O) = 16.00 g/mol - The molar mass of hydrogen (H) = 1.01
g/mol - Molar mass of KOH = 39.10 + 16.00 + 1.01 = 56.11 g/mol
2. Calculate the number of moles of KOH: - Number of moles =
given mass / molar mass = 50.0 g / 56.11 g/mol 0.891 mol
3. Use the mole ratio from the balanced equation to find the
number of moles of KCl: - From the balanced equation, 2 moles of
KOH produce 1 mole of KCl. So, 0.891 mol KOH will produce 0.891
/ 2 = 0.4455 mol KCl
4. Calculate the molar mass of KCl: - The molar mass of potassium
(K) = 39.10 g/mol - The molar mass of chlorine (Cl) = 35.45 g/mol
- Molar mass of KCl = 39.10 + 35.45 = 74.55 g/mol
5. Calculate the mass of KCl produced: - Mass = number of moles
Ö
molar mass = 0.4455 mol
Ö
74.55 g/mol 33.27 g
Therefore, when 50.0 g of KOH reacts, approximately 33.27 g of
KCl is produced.
Question 6
Step-by-step solution: 1. Calculate the molar mass of NaCl: Na:
1 atom x 22.99 g/mol = 22.99 g/mol Cl: 1 atom x 35.45 g/mol =
35.45 g/mol Molar mass of NaCl = 22.99 g/mol + 35.45 g/mol =
58.44 g/mol
2. Convert the mass of NaCl to moles: 25.0 g NaCl x (1 mol /
58.44 g) = 0.428 moles NaCl
3. Convert the volume of the solution to liters: 500.0 mL = 500.0
mL x (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity using the formula: Molarity (M) = moles
of solute / liters of solution Molarity = 0.428 moles / 0.500 L = 0.856
M
4
Therefore, the molarity of the solution is 0.856 M.Question 6: Cal-
culate the molarity of a solution that contains 25.0 grams of sodium
chloride (NaCl) dissolved in 500.0 mL of solution.
Step-by-step solution: 1. Calculate the molar mass of NaCl: Na:
1 atom x 22.99 g/mol = 22.99 g/mol Cl: 1 atom x 35.45 g/mol =
35.45 g/mol Molar mass of NaCl = 22.99 g/mol + 35.45 g/mol =
58.44 g/mol
2. Convert the mass of NaCl to moles: 25.0 g NaCl x (1 mol /
58.44 g) = 0.428 moles NaCl
3. Convert the volume of the solution to liters: 500.0 mL = 500.0
mL x (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity using the formula: Molarity (M) = moles
of solute / liters of solution Molarity = 0.428 moles / 0.500 L = 0.856
M
Therefore, the molarity of the solution is 0.856 M.
Question 7
Step 1: Determine the molar masses of each element present in
the compound. - Molar mass of potassium (K): 39.10 g/mol - Molar
mass of carbon (C): 12.01 g/mol - Molar mass of oxygen (O): 16.00
g/mol
Step 2: Calculate the molar mass of the entire compound by sum-
ming the molar masses of each element multiplied by their respective
subscripts in the chemical formula. Molar mass of K2CO3 = 2(K) +
1(C) + 3(O) Molar mass of K2CO3 = 2(39.10) + 12.01 + 3(16.00)
Molar mass of K2CO3 = 78.20 + 12.01 + 48.00 Molar mass of K2CO3
= 138.21 g/mol
Step 3: The molar mass of the compound K2CO3 is 138.21 g/mol.Question
7: What is the molar mass of a compound with the chemical formula
K2CO3?
Step 1: Determine the molar masses of each element present in
the compound. - Molar mass of potassium (K): 39.10 g/mol - Molar
mass of carbon (C): 12.01 g/mol - Molar mass of oxygen (O): 16.00
g/mol
Step 2: Calculate the molar mass of the entire compound by sum-
ming the molar masses of each element multiplied by their respective
subscripts in the chemical formula. Molar mass of K2CO3 = 2(K) +
1(C) + 3(O) Molar mass of K2CO3 = 2(39.10) + 12.01 + 3(16.00)
Molar mass of K2CO3 = 78.20 + 12.01 + 48.00 Molar mass of K2CO3
= 138.21 g/mol
Step 3: The molar mass of the compound K2CO3 is 138.21 g/mol.
5
Question 8
Step-by-step solution: 1. Calculate the molar mass of potassium
chloride (KCl): Molar mass of K = 39.10 g/mol Molar mass of Cl
= 35.45 g/mol Molar mass of KCl = 39.10 g/mol + 35.45 g/mol =
74.55 g/mol
2. Calculate the number of moles of potassium chloride in the
sample: Number of moles = Mass / Molar mass Number of moles =
25.0 g / 74.55 g/mol = 0.335 moles
3. Calculate the volume of the solution in liters: Volume = 500.0
mL = 500.0 mL * (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity of the solution: Molarity = Number of
moles / Volume of solution in liters Molarity = 0.335 moles / 0.500
L = 0.670 M
Therefore, the molarity of the resulting solution is 0.670 M.Question
8: A 25.0 g sample of potassium chloride (KCl) is dissolved in enough
water to make 500.0 mL of solution. Determine the molarity of the
resulting solution.
Step-by-step solution: 1. Calculate the molar mass of potassium
chloride (KCl): Molar mass of K = 39.10 g/mol Molar mass of Cl
= 35.45 g/mol Molar mass of KCl = 39.10 g/mol + 35.45 g/mol =
74.55 g/mol
2. Calculate the number of moles of potassium chloride in the
sample: Number of moles = Mass / Molar mass Number of moles =
25.0 g / 74.55 g/mol = 0.335 moles
3. Calculate the volume of the solution in liters: Volume = 500.0
mL = 500.0 mL * (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity of the solution: Molarity = Number of
moles / Volume of solution in liters Molarity = 0.335 moles / 0.500
L = 0.670 M
Therefore, the molarity of the resulting solution is 0.670 M.
Question 9
A sample of sodium chloride (NaCl) is dissolved in water to make
a 500 mL solution. The concentration of the solution is 0.2 M. What
is the mass of NaCl in the solution?
Step-by-step solution: 1. First, calculate the number of moles of
NaCl in the solution using the formula: Number of moles = con-
centration (M) x volume (L) Number of moles = 0.2 mol/L x 0.5 L
Number of moles = 0.1 mol
2. Next, use the molar mass of NaCl to convert moles to grams.
The molar mass of NaCl is 58.44 g/mol. Mass of NaCl = number of
moles x molar mass Mass of NaCl = 0.1 mol x 58.44 g/mol Mass of
NaCl = 5.844 g
6
Therefore, the mass of NaCl in the solution is 5.844 grams.Question
9:
A sample of sodium chloride (NaCl) is dissolved in water to make
a 500 mL solution. The concentration of the solution is 0.2 M. What
is the mass of NaCl in the solution?
Step-by-step solution: 1. First, calculate the number of moles of
NaCl in the solution using the formula: Number of moles = con-
centration (M) x volume (L) Number of moles = 0.2 mol/L x 0.5 L
Number of moles = 0.1 mol
2. Next, use the molar mass of NaCl to convert moles to grams.
The molar mass of NaCl is 58.44 g/mol. Mass of NaCl = number of
moles x molar mass Mass of NaCl = 0.1 mol x 58.44 g/mol Mass of
NaCl = 5.844 g
Therefore, the mass of NaCl in the solution is 5.844 grams.
Question 10
Step-by-step solution: 1. Calculate the molar mass of NaCl: -
Atomic mass of Na = 22.99 g/mol - Atomic mass of Cl = 35.45 g/mol
Molar mass of NaCl = 22.99 + 35.45 = 58.44 g/mol
2. Calculate the number of moles of NaCl in 25 grams: Number of
moles = Mass / Molar mass Number of moles = 25 g / 58.44 g/mol
0.428 moles
3. Convert the volume of the solution to liters: Volume = 500 mL
= 500 mL / 1000 mL/L = 0.5 L
4. Calculate the molarity of the solution: Molarity = Number of
moles / Volume of solution Molarity = 0.428 moles / 0.5 L = 0.856
M
Therefore, the molarity of the solution prepared by dissolving 25
grams of NaCl in enough water to make 500 mL of solution is 0.856
M.Question 10: Calculate the molarity of a solution prepared by
dissolving 25 grams of sodium chloride (NaCl) in enough water to
make 500 mL of solution.
Step-by-step solution: 1. Calculate the molar mass of NaCl: -
Atomic mass of Na = 22.99 g/mol - Atomic mass of Cl = 35.45 g/mol
Molar mass of NaCl = 22.99 + 35.45 = 58.44 g/mol
2. Calculate the number of moles of NaCl in 25 grams: Number of
moles = Mass / Molar mass Number of moles = 25 g / 58.44 g/mol
0.428 moles
3. Convert the volume of the solution to liters: Volume = 500 mL
= 500 mL / 1000 mL/L = 0.5 L
4. Calculate the molarity of the solution: Molarity = Number of
moles / Volume of solution Molarity = 0.428 moles / 0.5 L = 0.856
M
7
How many grams of NaCl would be needed to prepare 500 mL of this
solution?
Step-by-step solution: 1. Determine the molar mass of NaCl: Na:
22.99 g/mol Cl: 35.45 g/mol Molar mass of NaCl = 22.99 g/mol +
35.45 g/mol = 58.44 g/mol
2. Calculate the number of moles of NaCl needed to prepare 500
mL of 0.25 M solution: 0.25 moles/L * 0.5 L = 0.125 moles
3. Convert moles to grams using the molar mass of NaCl: 0.125
moles * 58.44 g/mol = 7.305 g
Therefore, the student would need 7.305 grams of NaCl to prepare
500 mL of a 0.25 M solution.
Question 3
Step-by-step solution: 1. Calculate the molar mass of sodium chlo-
ride (NaCl): - The molar mass of NaCl is the sum of the molar masses
of sodium (Na) and chlorine (Cl). - The molar mass of Na is approxi-
mately 22.99 g/mol, and the molar mass of Cl is approximately 35.45
g/mol. - Therefore, the molar mass of NaCl = 22.99 g/mol + 35.45
g/mol = 58.44 g/mol.
2. Determine the number of moles of NaCl: - Given mass of NaCl
= 25.0 grams - Number of moles = mass / molar mass - Number of
moles = 25.0 g / 58.44 g/mol 0.428 moles
3. Calculate the volume of the solution in liters: - Given volume
of solution = 500.0 mL = 500.0 cm
³
- Convert volume to liters: 500.0
cm
³
* (1 mL / 1 cm
³
) * (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity of the solution: - Molarity (M) = moles
of solute / volume of solution in liters - Molarity = 0.428 moles /
0.500 L 0.856 M
Therefore, the molarity of the solution containing 25.0 grams of
sodium chloride in 500.0 mL is approximately 0.856 M.Question 3:
Calculate the molarity of a solution that contains 25.0 grams of sodium
chloride (NaCl) dissolved in 500.0 mL of solution.
Step-by-step solution: 1. Calculate the molar mass of sodium chlo-
ride (NaCl): - The molar mass of NaCl is the sum of the molar masses
of sodium (Na) and chlorine (Cl). - The molar mass of Na is approxi-
mately 22.99 g/mol, and the molar mass of Cl is approximately 35.45
g/mol. - Therefore, the molar mass of NaCl = 22.99 g/mol + 35.45
g/mol = 58.44 g/mol.
2. Determine the number of moles of NaCl: - Given mass of NaCl
= 25.0 grams - Number of moles = mass / molar mass - Number of
moles = 25.0 g / 58.44 g/mol 0.428 moles
3. Calculate the volume of the solution in liters: - Given volume
of solution = 500.0 mL = 500.0 cm
³
- Convert volume to liters: 500.0
cm
³
* (1 mL / 1 cm
³
) * (1 L / 1000 mL) = 0.500 L
2
4. Calculate the molarity of the solution: - Molarity (M) = moles
of solute / volume of solution in liters - Molarity = 0.428 moles /
0.500 L 0.856 M
Therefore, the molarity of the solution containing 25.0 grams of
sodium chloride in 500.0 mL is approximately 0.856 M.
Question 4
Step-by-step solution: 1. Find the atomic mass of each element
present in sulfuric acid: - Hydrogen (H): Atomic mass = 1 g/mol -
Sulfur (S): Atomic mass = 32.06 g/mol - Oxygen (O): Atomic mass
= 16 g/mol
2. Determine the molecular formula of sulfuric acid, H2SO4. -
Multiply the atomic mass of hydrogen by 2: 2 * 1 g/mol = 2 g/mol
- Multiply the atomic mass of sulfur by 1: 1 * 32.06 g/mol = 32.06
g/mol - Multiply the atomic mass of oxygen by 4: 4 * 16 g/mol = 64
g/mol
3. Add the molar masses of each element to get the molar mass
of sulfuric acid: Molar mass of H2SO4 = 2 g/mol + 32.06 g/mol +
64 g/mol Molar mass of H2SO4 = 98.06 g/mol
Therefore, the molar mass of sulfuric acid, H2SO4, is 98.06 g/mol.Question
4: Calculate the molar mass of sulfuric acid, H2SO4.
Step-by-step solution: 1. Find the atomic mass of each element
present in sulfuric acid: - Hydrogen (H): Atomic mass = 1 g/mol -
Sulfur (S): Atomic mass = 32.06 g/mol - Oxygen (O): Atomic mass
= 16 g/mol
2. Determine the molecular formula of sulfuric acid, H2SO4. -
Multiply the atomic mass of hydrogen by 2: 2 * 1 g/mol = 2 g/mol
- Multiply the atomic mass of sulfur by 1: 1 * 32.06 g/mol = 32.06
g/mol - Multiply the atomic mass of oxygen by 4: 4 * 16 g/mol = 64
g/mol
3. Add the molar masses of each element to get the molar mass
of sulfuric acid: Molar mass of H2SO4 = 2 g/mol + 32.06 g/mol +
64 g/mol Molar mass of H2SO4 = 98.06 g/mol
Therefore, the molar mass of sulfuric acid, H2SO4, is 98.06 g/mol.
Question 5
Step-by-step solution: 1. Calculate the molar mass of KOH: - The
molar mass of potassium (K) = 39.10 g/mol - The molar mass of
oxygen (O) = 16.00 g/mol - The molar mass of hydrogen (H) = 1.01
g/mol - Molar mass of KOH = 39.10 + 16.00 + 1.01 = 56.11 g/mol
2. Calculate the number of moles of KOH: - Number of moles =
given mass / molar mass = 50.0 g / 56.11 g/mol 0.891 mol
3
3. Use the mole ratio from the balanced equation to find the
number of moles of KCl: - From the balanced equation, 2 moles of
KOH produce 1 mole of KCl. So, 0.891 mol KOH will produce 0.891
/ 2 = 0.4455 mol KCl
4. Calculate the molar mass of KCl: - The molar mass of potassium
(K) = 39.10 g/mol - The molar mass of chlorine (Cl) = 35.45 g/mol
- Molar mass of KCl = 39.10 + 35.45 = 74.55 g/mol
5. Calculate the mass of KCl produced: - Mass = number of moles
Ö
molar mass = 0.4455 mol
Ö
74.55 g/mol 33.27 g
Therefore, when 50.0 g of KOH reacts, approximately 33.27 g of
KCl is produced.Question 5: What mass of potassium chloride (KCl)
is produced when 50.0 g of potassium hydroxide (KOH) reacts with
excess hydrochloric acid (HCl) according to the following balanced
chemical equation? 2KOH + HCl
KCl + H2O
Step-by-step solution: 1. Calculate the molar mass of KOH: - The
molar mass of potassium (K) = 39.10 g/mol - The molar mass of
oxygen (O) = 16.00 g/mol - The molar mass of hydrogen (H) = 1.01
g/mol - Molar mass of KOH = 39.10 + 16.00 + 1.01 = 56.11 g/mol
2. Calculate the number of moles of KOH: - Number of moles =
given mass / molar mass = 50.0 g / 56.11 g/mol 0.891 mol
3. Use the mole ratio from the balanced equation to find the
number of moles of KCl: - From the balanced equation, 2 moles of
KOH produce 1 mole of KCl. So, 0.891 mol KOH will produce 0.891
/ 2 = 0.4455 mol KCl
4. Calculate the molar mass of KCl: - The molar mass of potassium
(K) = 39.10 g/mol - The molar mass of chlorine (Cl) = 35.45 g/mol
- Molar mass of KCl = 39.10 + 35.45 = 74.55 g/mol
5. Calculate the mass of KCl produced: - Mass = number of moles
Ö
molar mass = 0.4455 mol
Ö
74.55 g/mol 33.27 g
Therefore, when 50.0 g of KOH reacts, approximately 33.27 g of
KCl is produced.
Question 6
Step-by-step solution: 1. Calculate the molar mass of NaCl: Na:
1 atom x 22.99 g/mol = 22.99 g/mol Cl: 1 atom x 35.45 g/mol =
35.45 g/mol Molar mass of NaCl = 22.99 g/mol + 35.45 g/mol =
58.44 g/mol
2. Convert the mass of NaCl to moles: 25.0 g NaCl x (1 mol /
58.44 g) = 0.428 moles NaCl
3. Convert the volume of the solution to liters: 500.0 mL = 500.0
mL x (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity using the formula: Molarity (M) = moles
of solute / liters of solution Molarity = 0.428 moles / 0.500 L = 0.856
M
4
Therefore, the molarity of the solution is 0.856 M.Question 6: Cal-
culate the molarity of a solution that contains 25.0 grams of sodium
chloride (NaCl) dissolved in 500.0 mL of solution.
Step-by-step solution: 1. Calculate the molar mass of NaCl: Na:
1 atom x 22.99 g/mol = 22.99 g/mol Cl: 1 atom x 35.45 g/mol =
35.45 g/mol Molar mass of NaCl = 22.99 g/mol + 35.45 g/mol =
58.44 g/mol
2. Convert the mass of NaCl to moles: 25.0 g NaCl x (1 mol /
58.44 g) = 0.428 moles NaCl
3. Convert the volume of the solution to liters: 500.0 mL = 500.0
mL x (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity using the formula: Molarity (M) = moles
of solute / liters of solution Molarity = 0.428 moles / 0.500 L = 0.856
M
Therefore, the molarity of the solution is 0.856 M.
Question 7
Step 1: Determine the molar masses of each element present in
the compound. - Molar mass of potassium (K): 39.10 g/mol - Molar
mass of carbon (C): 12.01 g/mol - Molar mass of oxygen (O): 16.00
g/mol
Step 2: Calculate the molar mass of the entire compound by sum-
ming the molar masses of each element multiplied by their respective
subscripts in the chemical formula. Molar mass of K2CO3 = 2(K) +
1(C) + 3(O) Molar mass of K2CO3 = 2(39.10) + 12.01 + 3(16.00)
Molar mass of K2CO3 = 78.20 + 12.01 + 48.00 Molar mass of K2CO3
= 138.21 g/mol
Step 3: The molar mass of the compound K2CO3 is 138.21 g/mol.Question
7: What is the molar mass of a compound with the chemical formula
K2CO3?
Step 1: Determine the molar masses of each element present in
the compound. - Molar mass of potassium (K): 39.10 g/mol - Molar
mass of carbon (C): 12.01 g/mol - Molar mass of oxygen (O): 16.00
g/mol
Step 2: Calculate the molar mass of the entire compound by sum-
ming the molar masses of each element multiplied by their respective
subscripts in the chemical formula. Molar mass of K2CO3 = 2(K) +
1(C) + 3(O) Molar mass of K2CO3 = 2(39.10) + 12.01 + 3(16.00)
Molar mass of K2CO3 = 78.20 + 12.01 + 48.00 Molar mass of K2CO3
= 138.21 g/mol
Step 3: The molar mass of the compound K2CO3 is 138.21 g/mol.
5
Question 8
Step-by-step solution: 1. Calculate the molar mass of potassium
chloride (KCl): Molar mass of K = 39.10 g/mol Molar mass of Cl
= 35.45 g/mol Molar mass of KCl = 39.10 g/mol + 35.45 g/mol =
74.55 g/mol
2. Calculate the number of moles of potassium chloride in the
sample: Number of moles = Mass / Molar mass Number of moles =
25.0 g / 74.55 g/mol = 0.335 moles
3. Calculate the volume of the solution in liters: Volume = 500.0
mL = 500.0 mL * (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity of the solution: Molarity = Number of
moles / Volume of solution in liters Molarity = 0.335 moles / 0.500
L = 0.670 M
Therefore, the molarity of the resulting solution is 0.670 M.Question
8: A 25.0 g sample of potassium chloride (KCl) is dissolved in enough
water to make 500.0 mL of solution. Determine the molarity of the
resulting solution.
Step-by-step solution: 1. Calculate the molar mass of potassium
chloride (KCl): Molar mass of K = 39.10 g/mol Molar mass of Cl
= 35.45 g/mol Molar mass of KCl = 39.10 g/mol + 35.45 g/mol =
74.55 g/mol
2. Calculate the number of moles of potassium chloride in the
sample: Number of moles = Mass / Molar mass Number of moles =
25.0 g / 74.55 g/mol = 0.335 moles
3. Calculate the volume of the solution in liters: Volume = 500.0
mL = 500.0 mL * (1 L / 1000 mL) = 0.500 L
4. Calculate the molarity of the solution: Molarity = Number of
moles / Volume of solution in liters Molarity = 0.335 moles / 0.500
L = 0.670 M
Therefore, the molarity of the resulting solution is 0.670 M.
Question 9
A sample of sodium chloride (NaCl) is dissolved in water to make
a 500 mL solution. The concentration of the solution is 0.2 M. What
is the mass of NaCl in the solution?
Step-by-step solution: 1. First, calculate the number of moles of
NaCl in the solution using the formula: Number of moles = con-
centration (M) x volume (L) Number of moles = 0.2 mol/L x 0.5 L
Number of moles = 0.1 mol
2. Next, use the molar mass of NaCl to convert moles to grams.
The molar mass of NaCl is 58.44 g/mol. Mass of NaCl = number of
moles x molar mass Mass of NaCl = 0.1 mol x 58.44 g/mol Mass of
NaCl = 5.844 g
6
Therefore, the mass of NaCl in the solution is 5.844 grams.Question
9:
A sample of sodium chloride (NaCl) is dissolved in water to make
a 500 mL solution. The concentration of the solution is 0.2 M. What
is the mass of NaCl in the solution?
Step-by-step solution: 1. First, calculate the number of moles of
NaCl in the solution using the formula: Number of moles = con-
centration (M) x volume (L) Number of moles = 0.2 mol/L x 0.5 L
Number of moles = 0.1 mol
2. Next, use the molar mass of NaCl to convert moles to grams.
The molar mass of NaCl is 58.44 g/mol. Mass of NaCl = number of
moles x molar mass Mass of NaCl = 0.1 mol x 58.44 g/mol Mass of
NaCl = 5.844 g
Therefore, the mass of NaCl in the solution is 5.844 grams.
Question 10
Step-by-step solution: 1. Calculate the molar mass of NaCl: -
Atomic mass of Na = 22.99 g/mol - Atomic mass of Cl = 35.45 g/mol
Molar mass of NaCl = 22.99 + 35.45 = 58.44 g/mol
2. Calculate the number of moles of NaCl in 25 grams: Number of
moles = Mass / Molar mass Number of moles = 25 g / 58.44 g/mol
0.428 moles
3. Convert the volume of the solution to liters: Volume = 500 mL
= 500 mL / 1000 mL/L = 0.5 L
4. Calculate the molarity of the solution: Molarity = Number of
moles / Volume of solution Molarity = 0.428 moles / 0.5 L = 0.856
M
Therefore, the molarity of the solution prepared by dissolving 25
grams of NaCl in enough water to make 500 mL of solution is 0.856
M.Question 10: Calculate the molarity of a solution prepared by
dissolving 25 grams of sodium chloride (NaCl) in enough water to
make 500 mL of solution.
Step-by-step solution: 1. Calculate the molar mass of NaCl: -
Atomic mass of Na = 22.99 g/mol - Atomic mass of Cl = 35.45 g/mol
Molar mass of NaCl = 22.99 + 35.45 = 58.44 g/mol
2. Calculate the number of moles of NaCl in 25 grams: Number of
moles = Mass / Molar mass Number of moles = 25 g / 58.44 g/mol
0.428 moles
3. Convert the volume of the solution to liters: Volume = 500 mL
= 500 mL / 1000 mL/L = 0.5 L
4. Calculate the molarity of the solution: Molarity = Number of
moles / Volume of solution Molarity = 0.428 moles / 0.5 L = 0.856
M
7
Therefore, the molarity of the solution prepared by dissolving 25
grams of NaCl in enough water to make 500 mL of solution is 0.856
M.
8
