CHEM 121 - GENERAL CHEMISTRY I -
Amount of Substance Question Bank
Question 1
Step-by-step solution: Given: Amount of substance = 4.5 mol
The amount of substance in moles is already given as 4.5 mol. Therefore, the
amount of substance in moles is 4.5 mol.Question 1: Calculate the amount
of substance in moles if given 4.5 mol of a substance.
Step-by-step solution: Given: Amount of substance = 4.5 mol
The amount of substance in moles is already given as 4.5 mol.
Therefore, the amount of substance in moles is 4.5 mol.
Question 2
Calculate the amount of substance in moles of 3.50 grams of sodium
chloride (NaCl).
Step-by-step Solution:
1. Determine the molar mass of sodium chloride (NaCl). The
molar mass of sodium (Na) is 22.99 g/mol and the molar mass of
chlorine (Cl) is 35.45 g/mol. Therefore, the molar mass of N aCl =
22.99 g/mol + 35.45 g/mol = 58.44 g/mol.
2. Use the formula to calculate the amount of substance: Amount
of substance (in moles) = Mass / Molar mass Amount of substance
= 3.50 g / 58.44 g/mol Amount of substance 0.06 moles
Therefore, 3.50 grams of sodium chloride (NaCl) is approximately
equivalent to 0.06 moles.Question 2:
Calculate the amount of substance in moles of 3.50 grams of sodium
chloride (NaCl).
Step-by-step Solution:
1. Determine the molar mass of sodium chloride (NaCl). The
molar mass of sodium (Na) is 22.99 g/mol and the molar mass of
chlorine (Cl) is 35.45 g/mol. Therefore, the molar mass of N aCl =
22.99 g/mol + 35.45 g/mol = 58.44 g/mol.
2. Use the formula to calculate the amount of substance: Amount
of substance (in moles) = Mass / Molar mass Amount of substance
= 3.50 g / 58.44 g/mol Amount of substance 0.06 moles
1
Therefore, 3.50 grams of sodium chloride (NaCl) is approximately
equivalent to 0.06 moles.
Question 3
Calculate the amount of substance in moles if the mass of a sample
is 45 grams and the molar mass of the substance is 3.5 g/mol.
Step-by-step solution:
Given: Mass of the sample = 45 grams Molar mass of the sub-
stance = 3.5 g/mol
The amount of substance (in moles) can be calculated using the
formula:
Amount of substance (moles) =Mass (g)
Molar mass (g/mol)
Substitute the given values into the formula:
Amount of substance (moles) =45 g
3.5g/mol
Amount of substance (moles) =45
3.5
Amount of substance (moles) = 12.86 moles
Therefore, the amount of substance in moles is 12.86 moles.Question
3:
Calculate the amount of substance in moles if the mass of a sample
is 45 grams and the molar mass of the substance is 3.5 g/mol.
Step-by-step solution:
Given: Mass of the sample = 45 grams Molar mass of the sub-
stance = 3.5 g/mol
The amount of substance (in moles) can be calculated using the
formula:
Amount of substance (moles) =Mass (g)
Molar mass (g/mol)
Substitute the given values into the formula:
Amount of substance (moles) =45 g
3.5g/mol
Amount of substance (moles) =45
3.5
Amount of substance (moles) = 12.86 moles
Therefore, the amount of substance in moles is 12.86 moles.
2
Question 4
A student has a 250 mL solution of 0.5 M sulfuric acid, H2SO4.
Calculate the amount of sulfuric acid in moles present in the solution.
Step-by-step solution: 1. The concentration of sulfuric acid solu-
tion is given as 0.5 M, which means there are 0.5 moles of H2SO4 in
1 liter of solution. 2. Convert the volume of the solution to liters:
250 mL = 0.25 L. 3. Calculate the amount of sulfuric acid in moles
present in the solution using the formula:
Amount of substance (moles) =Volume (liters) ×Concentration (M)
Amount of substance (moles) = 0.25 L×0.5M= 0.125 mol
4. Therefore, there are 0.125 moles of sulfuric acid present in the 250
mL solution.Question 4:
A student has a 250 mL solution of 0.5 M sulfuric acid, H2SO4.
Calculate the amount of sulfuric acid in moles present in the solution.
Step-by-step solution: 1. The concentration of sulfuric acid solu-
tion is given as 0.5 M, which means there are 0.5 moles of H2SO4 in
1 liter of solution. 2. Convert the volume of the solution to liters:
250 mL = 0.25 L. 3. Calculate the amount of sulfuric acid in moles
present in the solution using the formula:
Amount of substance (moles) =Volume (liters) ×Concentration (M)
Amount of substance (moles) = 0.25 L×0.5M= 0.125 mol
4. Therefore, there are 0.125 moles of sulfuric acid present in the 250
mL solution.
Question 5
A sample of oxygen gas has a volume of 3.50 L at 25
°
C and 1.20
atm pressure. Calculate the amount of substance of oxygen gas in
moles.
Given: - Volume of oxygen gas, V= 3.50 L - Temperature, T=
25◦C= 298 K - Pressure, P= 1.20 atm - Universal gas constant, R=
0.0821 L·atm ·K−1·mol−1
Solution:
Step 1: Convert the temperature to Kelvin
T= 25◦C= 298 K
Step 2: Use the ideal gas law equation to calculate the amount of
substance (moles)
P V =nRT
3
n=P V
RT
n=(1.20 atm)(3.50 L)
(0.0821 L·atm ·K−1·mol−1)(298 K)
Step 3: Calculate the amount of substance (moles)
n=4.2
24.5058
n= 0.171 mol
Answer: The amount of substance of oxygen gas in the sample is
0.171 moles.Question 5:
A sample of oxygen gas has a volume of 3.50 L at 25
°
C and 1.20
atm pressure. Calculate the amount of substance of oxygen gas in
moles.
Given: - Volume of oxygen gas, V= 3.50 L - Temperature, T=
25◦C= 298 K - Pressure, P= 1.20 atm - Universal gas constant, R=
0.0821 L·atm ·K−1·mol−1
Solution:
Step 1: Convert the temperature to Kelvin
T= 25◦C= 298 K
Step 2: Use the ideal gas law equation to calculate the amount of
substance (moles)
P V =nRT
n=P V
RT
n=(1.20 atm)(3.50 L)
(0.0821 L·atm ·K−1·mol−1)(298 K)
Step 3: Calculate the amount of substance (moles)
n=4.2
24.5058
n= 0.171 mol
Answer: The amount of substance of oxygen gas in the sample is
0.171 moles.
4
Question 6
Calculate the amount of substance in moles of 2.5 grams of oxygen
gas (O2).
Step-by-step solution: 1. Determine the molar mass of oxygen gas
(O2). The molar mass of O2is 2×molar mass of oxygen. The molar
mass of oxygen (O) = 16.00 g/mol The molar mass of O2=2×16.00
= 32.00 g/mol
2. Convert the given mass of oxygen gas (O2) from grams to moles
using the molar mass: Number of moles = mass in grams
molar mass Number of
moles = 2.5g
32.00 g/mol Number of moles ≈0.0781 mol
Therefore, the amount of substance in moles of 2.5 grams of oxygen
gas (O2) is approximately 0.0781 moles.Question 6:
Calculate the amount of substance in moles of 2.5 grams of oxygen
gas (O2).
Step-by-step solution: 1. Determine the molar mass of oxygen gas
(O2). The molar mass of O2is 2×molar mass of oxygen. The molar
mass of oxygen (O) = 16.00 g/mol The molar mass of O2=2×16.00
= 32.00 g/mol
2. Convert the given mass of oxygen gas (O2) from grams to moles
using the molar mass: Number of moles = mass in grams
molar mass Number of
moles = 2.5g
32.00 g/mol Number of moles ≈0.0781 mol
Therefore, the amount of substance in moles of 2.5 grams of oxygen
gas (O2) is approximately 0.0781 moles.
Question 7
Step-by-step Solution: Given: 2.5 moles of carbon dioxide molecules,
CO2Molar mass of carbon dioxide, CO2: 44.01 g/mol
1. Determine the molar relationship between moles and molecules:
1 mole of any substance contains Avogadro’s number of molecules,
which is approximately 6.022 ×1023 molecules.
2. Calculate the number of molecules in 2.5 moles of carbon diox-
ide: Number of molecules = 2.5 moles ×Avogadro’s number Number
of molecules = 2.5 moles ×6.022 ×1023 molecules/mole
3. Calculate the amount of substance in moles of 2.5 moles of
carbon dioxide: Amount of substance (moles) = Mass / Molar mass
Amount of substance (moles) = 2.5 moles
Therefore, the amount of substance in moles of 2.5 moles of car-
bon dioxide molecules, CO2, is 2.5 moles.Question 7: Calculate the
amount of substance in moles of 2.5 moles of carbon dioxide molecules,
CO2.
Step-by-step Solution: Given: 2.5 moles of carbon dioxide molecules,
CO2Molar mass of carbon dioxide, CO2: 44.01 g/mol
5
1. Determine the molar relationship between moles and molecules:
1 mole of any substance contains Avogadro’s number of molecules,
which is approximately 6.022 ×1023 molecules.
2. Calculate the number of molecules in 2.5 moles of carbon diox-
ide: Number of molecules = 2.5 moles ×Avogadro’s number Number
of molecules = 2.5 moles ×6.022 ×1023 molecules/mole
3. Calculate the amount of substance in moles of 2.5 moles of
carbon dioxide: Amount of substance (moles) = Mass / Molar mass
Amount of substance (moles) = 2.5 moles
Therefore, the amount of substance in moles of 2.5 moles of carbon
dioxide molecules, CO2, is 2.5 moles.
Question 8
Calculate the amount of substance in moles for a sample containing
3.2×1023 atoms of sodium.
Step-by-step solution:
Given: Number of atoms of sodium = 3.2×1023
Avogadro’s number, NA= 6.022 ×1023 atoms/mol
1. Calculate the amount of substance in moles using the formula:
Amount of substance (moles) =Number of atoms
Avogadro’s number
Amount of substance (moles) =3.2×1023
6.022 ×1023
Amount of substance (moles) = 0.532 mol
Therefore, the amount of substance in moles for a sample contain-
ing 3.2×1023 atoms of sodium is 0.532 mol.Question 8:
Calculate the amount of substance in moles for a sample containing
3.2×1023 atoms of sodium.
Step-by-step solution:
Given: Number of atoms of sodium = 3.2×1023
Avogadro’s number, NA= 6.022 ×1023 atoms/mol
1. Calculate the amount of substance in moles using the formula:
Amount of substance (moles) =Number of atoms
Avogadro’s number
Amount of substance (moles) =3.2×1023
6.022 ×1023
Amount of substance (moles) = 0.532 mol
Therefore, the amount of substance in moles for a sample contain-
ing 3.2×1023 atoms of sodium is 0.532 mol.
6
Question 9
Step-by-step Solution: Given: Mass of sodium hydroxide (NaOH)
= 3.5 grams Molar mass of NaOH = 22.99 g/mol (for Na) + 16.00
g/mol (for O) + 1.01 g/mol (for H) = 40.00 g/mol
1. Use the formula to calculate moles:
Amount of substance (moles) =Given mass
Molar mass
2. Substitute the given values into the formula:
Amount of substance (moles) =3.5g
40.00 g/mol
3. Calculate the amount of substance in moles:
Amount of substance (moles) =3.5
40.00 = 0.0875 moles
Therefore, the amount of substance in moles when given 3.5 grams
of sodium hydroxide is 0.0875 moles.Question 9: Calculate the amount
of substance in moles when given 3.5 grams of sodium hydroxide
(NaOH).
Step-by-step Solution: Given: Mass of sodium hydroxide (NaOH)
= 3.5 grams Molar mass of NaOH = 22.99 g/mol (for Na) + 16.00
g/mol (for O) + 1.01 g/mol (for H) = 40.00 g/mol
1. Use the formula to calculate moles:
Amount of substance (moles) =Given mass
Molar mass
2. Substitute the given values into the formula:
Amount of substance (moles) =3.5g
40.00 g/mol
3. Calculate the amount of substance in moles:
Amount of substance (moles) =3.5
40.00 = 0.0875 moles
Therefore, the amount of substance in moles when given 3.5 grams
of sodium hydroxide is 0.0875 moles.
Question 10
Calculate the amount of substance in moles in 2.5 grams of carbon
dioxide (CO2).
Step-by-step solution:
7
1. Determine the molar mass of carbon dioxide (CO2): The molar
mass of C= 12.01 g/mol. The molar mass of O= 16.00 g/mol.
Molar mass of CO2= (12.01×1)+(16.00×2) = 12.01+32.00 = 44.01 g/mol.
2. Calculate the number of moles: Given mass = 2.5 grams.
Number of moles =Given mass
Molar mass =2.5
44.01 ≈0.0569 moles.
Therefore, the amount of substance in 2.5 grams of carbon dioxide
is approximately 0.0569 moles.Question 10:
Calculate the amount of substance in moles in 2.5 grams of carbon
dioxide (CO2).
Step-by-step solution:
1. Determine the molar mass of carbon dioxide (CO2): The molar
mass of C= 12.01 g/mol. The molar mass of O= 16.00 g/mol.
Molar mass of CO2= (12.01×1)+(16.00×2) = 12.01+32.00 = 44.01 g/mol.
2. Calculate the number of moles: Given mass = 2.5 grams.
Number of moles =Given mass
Molar mass =2.5
44.01 ≈0.0569 moles.
Therefore, the amount of substance in 2.5 grams of carbon dioxide
is approximately 0.0569 moles.
Question 11
Calculate the number of moles in 2.5 grams of potassium hydroxide
(KOH).
Step-by-step Solution:
Given: Mass of potassium hydroxide (KOH) = 2.5 grams
1. Determine the molar mass of potassium hydroxide (KOH):
Molar mass of KOH = atomic mass of K + atomic mass of O +
atomic mass of H Molar mass of KOH = 39.10 g/mol + 16.00 g/mol
+ 1.01 g/mol Molar mass of KOH = 56.11 g/mol
2. Use the formula to calculate the number of moles: Number of
moles = Mass / Molar mass Number of moles = 2.5 grams / 56.11
g/mol Number of moles 0.0446 moles
Therefore, there are approximately 0.0446 moles in 2.5 grams of
potassium hydroxide (KOH).Question 11:
Calculate the number of moles in 2.5 grams of potassium hydroxide
(KOH).
Step-by-step Solution:
Given: Mass of potassium hydroxide (KOH) = 2.5 grams
1. Determine the molar mass of potassium hydroxide (KOH):
Molar mass of KOH = atomic mass of K + atomic mass of O +
atomic mass of H Molar mass of KOH = 39.10 g/mol + 16.00 g/mol
+ 1.01 g/mol Molar mass of KOH = 56.11 g/mol
2. Use the formula to calculate the number of moles: Number of
moles = Mass / Molar mass Number of moles = 2.5 grams / 56.11
g/mol Number of moles 0.0446 moles
8
Therefore, there are approximately 0.0446 moles in 2.5 grams of
potassium hydroxide (KOH).
Question 12
Step-by-step solution: 1. Write down the given information: -
Mass of iron: 10.0 g - Amount of iron atoms: 0.179 mol
2. Calculate the molar mass using the formula:
Molar mass =Mass
Amount of substance
3. Substitute the values into the formula:
Molar mass =10.0g
0.179 mol
4. Perform the division to find the molar mass:
Molar mass =10.0
0.179 ≈55.87 g/mol
Therefore, the molar mass of iron is approximately 55.87 g/mol.Question
12: A sample of iron with a mass of 10.0 g contains 0.179 mol of iron
atoms. Calculate the molar mass of iron.
Step-by-step solution: 1. Write down the given information: -
Mass of iron: 10.0 g - Amount of iron atoms: 0.179 mol
2. Calculate the molar mass using the formula:
Molar mass =Mass
Amount of substance
3. Substitute the values into the formula:
Molar mass =10.0g
0.179 mol
4. Perform the division to find the molar mass:
Molar mass =10.0
0.179 ≈55.87 g/mol
Therefore, the molar mass of iron is approximately 55.87 g/mol.
Question 13
Calculate the amount of substance in moles when given the fol-
lowing mass of a substance:
Mass of substance = 25.6 grams Molar mass of the substance =
32.0 g/mol
9
Step-by-step Solution:
1. Write down the given information: Mass of substance = 25.6
grams Molar mass of the substance = 32.0 g/mol
2. Use the formula to calculate the amount of substance in moles:
Amount of substance (moles) = Mass of substance / Molar mass
3. Substitute the given values into the formula: Amount of sub-
stance (moles) = 25.6 g / 32.0 g/mol
4. Calculate the amount of substance in moles: Amount of sub-
stance (moles) = 0.8 moles
Therefore, the amount of substance in moles is 0.8 moles.Question
13:
Calculate the amount of substance in moles when given the fol-
lowing mass of a substance:
Mass of substance = 25.6 grams Molar mass of the substance =
32.0 g/mol
Step-by-step Solution:
1. Write down the given information: Mass of substance = 25.6
grams Molar mass of the substance = 32.0 g/mol
2. Use the formula to calculate the amount of substance in moles:
Amount of substance (moles) = Mass of substance / Molar mass
3. Substitute the given values into the formula: Amount of sub-
stance (moles) = 25.6 g / 32.0 g/mol
4. Calculate the amount of substance in moles: Amount of sub-
stance (moles) = 0.8 moles
Therefore, the amount of substance in moles is 0.8 moles.
Question 14
Step-by-step solution: To calculate the amount of substance in
moles, we can use Avogadro’s number, which is 6.02 ×1023 mol−1.
Given that we have 6.02×1023 atoms of carbon, we can directly convert
this to moles by dividing by Avogadro’s number:
Amount of substance (moles) =6.02 ×1023 atoms
6.02 ×1023 mol−1
Amount of substance (moles) = 1 mol
Therefore, the amount of substance in 6.02
Ö
10
²³
atoms of carbon
is 1 mole.Question 14: Calculate the amount of substance in moles in
6.02
Ö
10
²³
atoms of carbon.
Step-by-step solution: To calculate the amount of substance in
moles, we can use Avogadro’s number, which is 6.02 ×1023 mol−1.
Given that we have 6.02×1023 atoms of carbon, we can directly convert
this to moles by dividing by Avogadro’s number:
10
Amount of substance (moles) =6.02 ×1023 atoms
6.02 ×1023 mol−1
Amount of substance (moles) = 1 mol
Therefore, the amount of substance in 6.02
Ö
10
²³
atoms of carbon
is 1 mole.
Question 15
Step-by-step solution: 1. Determine the molar mass of calcium
carbonate (CaCO):
Ca : 40.08 g/mol
C: 12.01 g/mol
O: 16.00 g/mol
Adding these molar masses:
40.08 + 12.01 + (16.00 ×3) = 100.09 g/mol
2. Calculate the number of moles using the formula:
Amount of substance (moles) =Mass (g)
Molar mass (g/mol)
Substitute the given values:
Amount of substance (moles) =3.5g
100.09 g/mol
Amount of substance (moles) = 0.035 mol
Therefore, the amount of substance in moles for 3.5 grams of cal-
cium carbonate is 0.035 moles.Question 15: Calculate the amount of
substance in moles if 3.5 grams of calcium carbonate (CaCO) is given.
Step-by-step solution: 1. Determine the molar mass of calcium
carbonate (CaCO):
Ca : 40.08 g/mol
C: 12.01 g/mol
O: 16.00 g/mol
Adding these molar masses:
40.08 + 12.01 + (16.00 ×3) = 100.09 g/mol
11
2. Calculate the number of moles using the formula:
Amount of substance (moles) =Mass (g)
Molar mass (g/mol)
Substitute the given values:
Amount of substance (moles) =3.5g
100.09 g/mol
Amount of substance (moles) = 0.035 mol
Therefore, the amount of substance in moles for 3.5 grams of cal-
cium carbonate is 0.035 moles.
Question 16
Calculate the amount of substance in moles present in a sam-
ple containing 3.50 ×1023 atoms of silver. (Atomic mass of silver =
107.87 g/mol)
Step-by-step solution:
Given: Number of atoms of silver = 3.50 ×1023 Atomic mass of
silver = 107.87 g/mol
To calculate the amount of substance in moles, we can use the
following formula:
Amount of substance (in moles) =Number of atoms
Avogadro’s number
First, we need to convert the number of atoms to moles using
Avogadro’s number:
Amount of substance (in moles) =3.50 ×1023 atoms
6.022 ×1023 atoms/mol
Amount of substance (in moles) =3.50 ×1023
6.022 ×1023 moles
Amount of substance (in moles) = 0.581 moles
Therefore, the amount of substance in moles present in the sample
containing 3.50 ×1023 atoms of silver is 0.581 moles.Question 16:
Calculate the amount of substance in moles present in a sam-
ple containing 3.50 ×1023 atoms of silver. (Atomic mass of silver =
107.87 g/mol)
Step-by-step solution:
Given: Number of atoms of silver = 3.50 ×1023 Atomic mass of
silver = 107.87 g/mol
12
To calculate the amount of substance in moles, we can use the
following formula:
Amount of substance (in moles) =Number of atoms
Avogadro’s number
First, we need to convert the number of atoms to moles using
Avogadro’s number:
Amount of substance (in moles) =3.50 ×1023 atoms
6.022 ×1023 atoms/mol
Amount of substance (in moles) =3.50 ×1023
6.022 ×1023 moles
Amount of substance (in moles) = 0.581 moles
Therefore, the amount of substance in moles present in the sample
containing 3.50 ×1023 atoms of silver is 0.581 moles.
Question 17
Step-by-step Solution: Given: Number of particles = 1.8×1023
We know that 1 mole of any substance contains Avogadro’s number
of particles, which is 6.022 ×1023 particles.
To calculate the amount of substance in moles, we can use the
following formula:
Amount of substance (moles) =Number of particles
6.022 ×1023
Plugging in the given values:
Amount of substance (moles) =1.8×1023
6.022 ×1023
Amount of substance (moles) = 0.299 moles
Therefore, the amount of substance in moles when 1.8×1023 parti-
cles are present is 0.299 moles.Question 17: Calculate the amount of
substance in moles when 1.8
Ö
1023particlesofasubstancearepresent.
Step-by-step Solution: Given: Number of particles = 1.8×1023
We know that 1 mole of any substance contains Avogadro’s number
of particles, which is 6.022 ×1023 particles.
To calculate the amount of substance in moles, we can use the
following formula:
Amount of substance (moles) =Number of particles
6.022 ×1023
13
Plugging in the given values:
Amount of substance (moles) =1.8×1023
6.022 ×1023
Amount of substance (moles) = 0.299 moles
Therefore, the amount of substance in moles when 1.8×1023 par-
ticles are present is 0.299 moles.
Question 18
Calculate the amount of substance in moles when given the fol-
lowing information:
Mass of the substance = 48.5 g Molar mass of the substance = 32
g/mol
Step-by-step solution:
1. Write down the given values: Mass of the substance = 48.5 g
Molar mass of the substance = 32 g/mol
2. Use the formula to calculate the amount of substance in moles:
Amount of substance (moles) = Mass / Molar mass
3. Substitute the given values into the formula: Amount of sub-
stance (moles) = 48.5 g / 32 g/mol
4. Perform the division to find the amount of substance in moles:
Amount of substance (moles) = 1.515 moles
Therefore, the amount of substance in moles is 1.515 moles.Question
18:
Calculate the amount of substance in moles when given the fol-
lowing information:
Mass of the substance = 48.5 g Molar mass of the substance = 32
g/mol
Step-by-step solution:
1. Write down the given values: Mass of the substance = 48.5 g
Molar mass of the substance = 32 g/mol
2. Use the formula to calculate the amount of substance in moles:
Amount of substance (moles) = Mass / Molar mass
3. Substitute the given values into the formula: Amount of sub-
stance (moles) = 48.5 g / 32 g/mol
4. Perform the division to find the amount of substance in moles:
Amount of substance (moles) = 1.515 moles
Therefore, the amount of substance in moles is 1.515 moles.
Question 19
Question 19: Calculate the amount of substance in moles present
in 3.0 grams of oxygen gas, O2.
14
Solution: Given: Mass of oxygen gas, O2= 3.0 grams Molar mass
of O2= 32 g/mol (Oxygen has a molar mass of 16 g/mol, and since
there are two oxygen atoms in O2, the molar mass of O2is 2 * 16 =
32 g/mol)
To find the amount of substance in moles, we can use the formula:
Amount of substance (in moles) =Mass
Molar mass
Substitute the given values into the formula:
Amount of substance (in moles) =3.0grams
32 g/mol
Amount of substance (in moles) = 0.09375 moles
Therefore, the amount of substance in moles present in 3.0 grams
of oxygen gas, O2, is 0.09375 moles.Certainly! Here is a question along
with its step-by-step solution on Amount of Substance, in LateX code,
for Liberty University.
Question 19: Calculate the amount of substance in moles present
in 3.0 grams of oxygen gas, O2.
Solution: Given: Mass of oxygen gas, O2= 3.0 grams Molar mass
of O2= 32 g/mol (Oxygen has a molar mass of 16 g/mol, and since
there are two oxygen atoms in O2, the molar mass of O2is 2 * 16 =
32 g/mol)
To find the amount of substance in moles, we can use the formula:
Amount of substance (in moles) =Mass
Molar mass
Substitute the given values into the formula:
Amount of substance (in moles) =3.0grams
32 g/mol
Amount of substance (in moles) = 0.09375 moles
Therefore, the amount of substance in moles present in 3.0 grams
of oxygen gas, O2, is 0.09375 moles.
Question 20
Given that the molar mass of carbon is 12 g/mol, determine the
amount of substance in moles of 36 g of carbon.
Step-by-step solution:
1. Determine the number of moles using the formula:
Amount of substance (in moles) =Mass (in grams)
Molar mass (in g/mol)
15
2. Substitute the given values:
Amount of substance (in moles) =36 g
12 g/mol = 3 moles
Therefore, the amount of substance in 36 g of carbon is 3 moles.Question
20:
Given that the molar mass of carbon is 12 g/mol, determine the
amount of substance in moles of 36 g of carbon.
Step-by-step solution:
1. Determine the number of moles using the formula:
Amount of substance (in moles) =Mass (in grams)
Molar mass (in g/mol)
2. Substitute the given values:
Amount of substance (in moles) =36 g
12 g/mol = 3 moles
Therefore, the amount of substance in 36 g of carbon is 3 moles.
16
Therefore, 3.50 grams of sodium chloride (NaCl) is approximately
equivalent to 0.06 moles.
Question 3
Calculate the amount of substance in moles if the mass of a sample
is 45 grams and the molar mass of the substance is 3.5 g/mol.
Step-by-step solution:
Given: Mass of the sample = 45 grams Molar mass of the sub-
stance = 3.5 g/mol
The amount of substance (in moles) can be calculated using the
formula:
Amount of substance (moles) =Mass (g)
Molar mass (g/mol)
Substitute the given values into the formula:
Amount of substance (moles) =45 g
3.5g/mol
Amount of substance (moles) =45
3.5
Amount of substance (moles) = 12.86 moles
Therefore, the amount of substance in moles is 12.86 moles.Question
3:
Calculate the amount of substance in moles if the mass of a sample
is 45 grams and the molar mass of the substance is 3.5 g/mol.
Step-by-step solution:
Given: Mass of the sample = 45 grams Molar mass of the sub-
stance = 3.5 g/mol
The amount of substance (in moles) can be calculated using the
formula:
Amount of substance (moles) =Mass (g)
Molar mass (g/mol)
Substitute the given values into the formula:
Amount of substance (moles) =45 g
3.5g/mol
Amount of substance (moles) =45
3.5
Amount of substance (moles) = 12.86 moles
Therefore, the amount of substance in moles is 12.86 moles.
2
Question 4
A student has a 250 mL solution of 0.5 M sulfuric acid, H2SO4.
Calculate the amount of sulfuric acid in moles present in the solution.
Step-by-step solution: 1. The concentration of sulfuric acid solu-
tion is given as 0.5 M, which means there are 0.5 moles of H2SO4 in
1 liter of solution. 2. Convert the volume of the solution to liters:
250 mL = 0.25 L. 3. Calculate the amount of sulfuric acid in moles
present in the solution using the formula:
Amount of substance (moles) =Volume (liters) ×Concentration (M)
Amount of substance (moles) = 0.25 L×0.5M= 0.125 mol
4. Therefore, there are 0.125 moles of sulfuric acid present in the 250
mL solution.Question 4:
A student has a 250 mL solution of 0.5 M sulfuric acid, H2SO4.
Calculate the amount of sulfuric acid in moles present in the solution.
Step-by-step solution: 1. The concentration of sulfuric acid solu-
tion is given as 0.5 M, which means there are 0.5 moles of H2SO4 in
1 liter of solution. 2. Convert the volume of the solution to liters:
250 mL = 0.25 L. 3. Calculate the amount of sulfuric acid in moles
present in the solution using the formula:
Amount of substance (moles) =Volume (liters) ×Concentration (M)
Amount of substance (moles) = 0.25 L×0.5M= 0.125 mol
4. Therefore, there are 0.125 moles of sulfuric acid present in the 250
mL solution.
Question 5
A sample of oxygen gas has a volume of 3.50 L at 25
°
C and 1.20
atm pressure. Calculate the amount of substance of oxygen gas in
moles.
Given: - Volume of oxygen gas, V= 3.50 L - Temperature, T=
25◦C= 298 K - Pressure, P= 1.20 atm - Universal gas constant, R=
0.0821 L·atm ·K−1·mol−1
Solution:
Step 1: Convert the temperature to Kelvin
T= 25◦C= 298 K
Step 2: Use the ideal gas law equation to calculate the amount of
substance (moles)
P V =nRT
3
n=P V
RT
n=(1.20 atm)(3.50 L)
(0.0821 L·atm ·K−1·mol−1)(298 K)
Step 3: Calculate the amount of substance (moles)
n=4.2
24.5058
n= 0.171 mol
Answer: The amount of substance of oxygen gas in the sample is
0.171 moles.Question 5:
A sample of oxygen gas has a volume of 3.50 L at 25
°
C and 1.20
atm pressure. Calculate the amount of substance of oxygen gas in
moles.
Given: - Volume of oxygen gas, V= 3.50 L - Temperature, T=
25◦C= 298 K - Pressure, P= 1.20 atm - Universal gas constant, R=
0.0821 L·atm ·K−1·mol−1
Solution:
Step 1: Convert the temperature to Kelvin
T= 25◦C= 298 K
Step 2: Use the ideal gas law equation to calculate the amount of
substance (moles)
P V =nRT
n=P V
RT
n=(1.20 atm)(3.50 L)
(0.0821 L·atm ·K−1·mol−1)(298 K)
Step 3: Calculate the amount of substance (moles)
n=4.2
24.5058
n= 0.171 mol
Answer: The amount of substance of oxygen gas in the sample is
0.171 moles.
4
Question 6
Calculate the amount of substance in moles of 2.5 grams of oxygen
gas (O2).
Step-by-step solution: 1. Determine the molar mass of oxygen gas
(O2). The molar mass of O2is 2×molar mass of oxygen. The molar
mass of oxygen (O) = 16.00 g/mol The molar mass of O2=2×16.00
= 32.00 g/mol
2. Convert the given mass of oxygen gas (O2) from grams to moles
using the molar mass: Number of moles = mass in grams
molar mass Number of
moles = 2.5g
32.00 g/mol Number of moles ≈0.0781 mol
Therefore, the amount of substance in moles of 2.5 grams of oxygen
gas (O2) is approximately 0.0781 moles.Question 6:
Calculate the amount of substance in moles of 2.5 grams of oxygen
gas (O2).
Step-by-step solution: 1. Determine the molar mass of oxygen gas
(O2). The molar mass of O2is 2×molar mass of oxygen. The molar
mass of oxygen (O) = 16.00 g/mol The molar mass of O2=2×16.00
= 32.00 g/mol
2. Convert the given mass of oxygen gas (O2) from grams to moles
using the molar mass: Number of moles = mass in grams
molar mass Number of
moles = 2.5g
32.00 g/mol Number of moles ≈0.0781 mol
Therefore, the amount of substance in moles of 2.5 grams of oxygen
gas (O2) is approximately 0.0781 moles.
Question 7
Step-by-step Solution: Given: 2.5 moles of carbon dioxide molecules,
CO2Molar mass of carbon dioxide, CO2: 44.01 g/mol
1. Determine the molar relationship between moles and molecules:
1 mole of any substance contains Avogadro’s number of molecules,
which is approximately 6.022 ×1023 molecules.
2. Calculate the number of molecules in 2.5 moles of carbon diox-
ide: Number of molecules = 2.5 moles ×Avogadro’s number Number
of molecules = 2.5 moles ×6.022 ×1023 molecules/mole
3. Calculate the amount of substance in moles of 2.5 moles of
carbon dioxide: Amount of substance (moles) = Mass / Molar mass
Amount of substance (moles) = 2.5 moles
Therefore, the amount of substance in moles of 2.5 moles of car-
bon dioxide molecules, CO2, is 2.5 moles.Question 7: Calculate the
amount of substance in moles of 2.5 moles of carbon dioxide molecules,
CO2.
Step-by-step Solution: Given: 2.5 moles of carbon dioxide molecules,
CO2Molar mass of carbon dioxide, CO2: 44.01 g/mol
5
1. Determine the molar relationship between moles and molecules:
1 mole of any substance contains Avogadro’s number of molecules,
which is approximately 6.022 ×1023 molecules.
2. Calculate the number of molecules in 2.5 moles of carbon diox-
ide: Number of molecules = 2.5 moles ×Avogadro’s number Number
of molecules = 2.5 moles ×6.022 ×1023 molecules/mole
3. Calculate the amount of substance in moles of 2.5 moles of
carbon dioxide: Amount of substance (moles) = Mass / Molar mass
Amount of substance (moles) = 2.5 moles
Therefore, the amount of substance in moles of 2.5 moles of carbon
dioxide molecules, CO2, is 2.5 moles.
Question 8
Calculate the amount of substance in moles for a sample containing
3.2×1023 atoms of sodium.
Step-by-step solution:
Given: Number of atoms of sodium = 3.2×1023
Avogadro’s number, NA= 6.022 ×1023 atoms/mol
1. Calculate the amount of substance in moles using the formula:
Amount of substance (moles) =Number of atoms
Avogadro’s number
Amount of substance (moles) =3.2×1023
6.022 ×1023
Amount of substance (moles) = 0.532 mol
Therefore, the amount of substance in moles for a sample contain-
ing 3.2×1023 atoms of sodium is 0.532 mol.Question 8:
Calculate the amount of substance in moles for a sample containing
3.2×1023 atoms of sodium.
Step-by-step solution:
Given: Number of atoms of sodium = 3.2×1023
Avogadro’s number, NA= 6.022 ×1023 atoms/mol
1. Calculate the amount of substance in moles using the formula:
Amount of substance (moles) =Number of atoms
Avogadro’s number
Amount of substance (moles) =3.2×1023
6.022 ×1023
Amount of substance (moles) = 0.532 mol
Therefore, the amount of substance in moles for a sample contain-
ing 3.2×1023 atoms of sodium is 0.532 mol.
6
Question 9
Step-by-step Solution: Given: Mass of sodium hydroxide (NaOH)
= 3.5 grams Molar mass of NaOH = 22.99 g/mol (for Na) + 16.00
g/mol (for O) + 1.01 g/mol (for H) = 40.00 g/mol
1. Use the formula to calculate moles:
Amount of substance (moles) =Given mass
Molar mass
2. Substitute the given values into the formula:
Amount of substance (moles) =3.5g
40.00 g/mol
3. Calculate the amount of substance in moles:
Amount of substance (moles) =3.5
40.00 = 0.0875 moles
Therefore, the amount of substance in moles when given 3.5 grams
of sodium hydroxide is 0.0875 moles.Question 9: Calculate the amount
of substance in moles when given 3.5 grams of sodium hydroxide
(NaOH).
Step-by-step Solution: Given: Mass of sodium hydroxide (NaOH)
= 3.5 grams Molar mass of NaOH = 22.99 g/mol (for Na) + 16.00
g/mol (for O) + 1.01 g/mol (for H) = 40.00 g/mol
1. Use the formula to calculate moles:
Amount of substance (moles) =Given mass
Molar mass
2. Substitute the given values into the formula:
Amount of substance (moles) =3.5g
40.00 g/mol
3. Calculate the amount of substance in moles:
Amount of substance (moles) =3.5
40.00 = 0.0875 moles
Therefore, the amount of substance in moles when given 3.5 grams
of sodium hydroxide is 0.0875 moles.
Question 10
Calculate the amount of substance in moles in 2.5 grams of carbon
dioxide (CO2).
Step-by-step solution:
7
1. Determine the molar mass of carbon dioxide (CO2): The molar
mass of C= 12.01 g/mol. The molar mass of O= 16.00 g/mol.
Molar mass of CO2= (12.01×1)+(16.00×2) = 12.01+32.00 = 44.01 g/mol.
2. Calculate the number of moles: Given mass = 2.5 grams.
Number of moles =Given mass
Molar mass =2.5
44.01 ≈0.0569 moles.
Therefore, the amount of substance in 2.5 grams of carbon dioxide
is approximately 0.0569 moles.Question 10:
Calculate the amount of substance in moles in 2.5 grams of carbon
dioxide (CO2).
Step-by-step solution:
1. Determine the molar mass of carbon dioxide (CO2): The molar
mass of C= 12.01 g/mol. The molar mass of O= 16.00 g/mol.
Molar mass of CO2= (12.01×1)+(16.00×2) = 12.01+32.00 = 44.01 g/mol.
2. Calculate the number of moles: Given mass = 2.5 grams.
Number of moles =Given mass
Molar mass =2.5
44.01 ≈0.0569 moles.
Therefore, the amount of substance in 2.5 grams of carbon dioxide
is approximately 0.0569 moles.
Question 11
Calculate the number of moles in 2.5 grams of potassium hydroxide
(KOH).
Step-by-step Solution:
Given: Mass of potassium hydroxide (KOH) = 2.5 grams
1. Determine the molar mass of potassium hydroxide (KOH):
Molar mass of KOH = atomic mass of K + atomic mass of O +
atomic mass of H Molar mass of KOH = 39.10 g/mol + 16.00 g/mol
+ 1.01 g/mol Molar mass of KOH = 56.11 g/mol
2. Use the formula to calculate the number of moles: Number of
moles = Mass / Molar mass Number of moles = 2.5 grams / 56.11
g/mol Number of moles 0.0446 moles
Therefore, there are approximately 0.0446 moles in 2.5 grams of
potassium hydroxide (KOH).Question 11:
Calculate the number of moles in 2.5 grams of potassium hydroxide
(KOH).
Step-by-step Solution:
Given: Mass of potassium hydroxide (KOH) = 2.5 grams
1. Determine the molar mass of potassium hydroxide (KOH):
Molar mass of KOH = atomic mass of K + atomic mass of O +
atomic mass of H Molar mass of KOH = 39.10 g/mol + 16.00 g/mol
+ 1.01 g/mol Molar mass of KOH = 56.11 g/mol
2. Use the formula to calculate the number of moles: Number of
moles = Mass / Molar mass Number of moles = 2.5 grams / 56.11
g/mol Number of moles 0.0446 moles
8
Therefore, there are approximately 0.0446 moles in 2.5 grams of
potassium hydroxide (KOH).
Question 12
Step-by-step solution: 1. Write down the given information: -
Mass of iron: 10.0 g - Amount of iron atoms: 0.179 mol
2. Calculate the molar mass using the formula:
Molar mass =Mass
Amount of substance
3. Substitute the values into the formula:
Molar mass =10.0g
0.179 mol
4. Perform the division to find the molar mass:
Molar mass =10.0
0.179 ≈55.87 g/mol
Therefore, the molar mass of iron is approximately 55.87 g/mol.Question
12: A sample of iron with a mass of 10.0 g contains 0.179 mol of iron
atoms. Calculate the molar mass of iron.
Step-by-step solution: 1. Write down the given information: -
Mass of iron: 10.0 g - Amount of iron atoms: 0.179 mol
2. Calculate the molar mass using the formula:
Molar mass =Mass
Amount of substance
3. Substitute the values into the formula:
Molar mass =10.0g
0.179 mol
4. Perform the division to find the molar mass:
Molar mass =10.0
0.179 ≈55.87 g/mol
Therefore, the molar mass of iron is approximately 55.87 g/mol.
Question 13
Calculate the amount of substance in moles when given the fol-
lowing mass of a substance:
Mass of substance = 25.6 grams Molar mass of the substance =
32.0 g/mol
9
Step-by-step Solution:
1. Write down the given information: Mass of substance = 25.6
grams Molar mass of the substance = 32.0 g/mol
2. Use the formula to calculate the amount of substance in moles:
Amount of substance (moles) = Mass of substance / Molar mass
3. Substitute the given values into the formula: Amount of sub-
stance (moles) = 25.6 g / 32.0 g/mol
4. Calculate the amount of substance in moles: Amount of sub-
stance (moles) = 0.8 moles
Therefore, the amount of substance in moles is 0.8 moles.Question
13:
Calculate the amount of substance in moles when given the fol-
lowing mass of a substance:
Mass of substance = 25.6 grams Molar mass of the substance =
32.0 g/mol
Step-by-step Solution:
1. Write down the given information: Mass of substance = 25.6
grams Molar mass of the substance = 32.0 g/mol
2. Use the formula to calculate the amount of substance in moles:
Amount of substance (moles) = Mass of substance / Molar mass
3. Substitute the given values into the formula: Amount of sub-
stance (moles) = 25.6 g / 32.0 g/mol
4. Calculate the amount of substance in moles: Amount of sub-
stance (moles) = 0.8 moles
Therefore, the amount of substance in moles is 0.8 moles.
Question 14
Step-by-step solution: To calculate the amount of substance in
moles, we can use Avogadro’s number, which is 6.02 ×1023 mol−1.
Given that we have 6.02×1023 atoms of carbon, we can directly convert
this to moles by dividing by Avogadro’s number:
Amount of substance (moles) =6.02 ×1023 atoms
6.02 ×1023 mol−1
Amount of substance (moles) = 1 mol
Therefore, the amount of substance in 6.02
Ö
10
²³
atoms of carbon
is 1 mole.Question 14: Calculate the amount of substance in moles in
6.02
Ö
10
²³
atoms of carbon.
Step-by-step solution: To calculate the amount of substance in
moles, we can use Avogadro’s number, which is 6.02 ×1023 mol−1.
Given that we have 6.02×1023 atoms of carbon, we can directly convert
this to moles by dividing by Avogadro’s number:
10
Amount of substance (moles) =6.02 ×1023 atoms
6.02 ×1023 mol−1
Amount of substance (moles) = 1 mol
Therefore, the amount of substance in 6.02
Ö
10
²³
atoms of carbon
is 1 mole.
Question 15
Step-by-step solution: 1. Determine the molar mass of calcium
carbonate (CaCO):
Ca : 40.08 g/mol
C: 12.01 g/mol
O: 16.00 g/mol
Adding these molar masses:
40.08 + 12.01 + (16.00 ×3) = 100.09 g/mol
2. Calculate the number of moles using the formula:
Amount of substance (moles) =Mass (g)
Molar mass (g/mol)
Substitute the given values:
Amount of substance (moles) =3.5g
100.09 g/mol
Amount of substance (moles) = 0.035 mol
Therefore, the amount of substance in moles for 3.5 grams of cal-
cium carbonate is 0.035 moles.Question 15: Calculate the amount of
substance in moles if 3.5 grams of calcium carbonate (CaCO) is given.
Step-by-step solution: 1. Determine the molar mass of calcium
carbonate (CaCO):
Ca : 40.08 g/mol
C: 12.01 g/mol
O: 16.00 g/mol
Adding these molar masses:
40.08 + 12.01 + (16.00 ×3) = 100.09 g/mol
11
2. Calculate the number of moles using the formula:
Amount of substance (moles) =Mass (g)
Molar mass (g/mol)
Substitute the given values:
Amount of substance (moles) =3.5g
100.09 g/mol
Amount of substance (moles) = 0.035 mol
Therefore, the amount of substance in moles for 3.5 grams of cal-
cium carbonate is 0.035 moles.
Question 16
Calculate the amount of substance in moles present in a sam-
ple containing 3.50 ×1023 atoms of silver. (Atomic mass of silver =
107.87 g/mol)
Step-by-step solution:
Given: Number of atoms of silver = 3.50 ×1023 Atomic mass of
silver = 107.87 g/mol
To calculate the amount of substance in moles, we can use the
following formula:
Amount of substance (in moles) =Number of atoms
Avogadro’s number
First, we need to convert the number of atoms to moles using
Avogadro’s number:
Amount of substance (in moles) =3.50 ×1023 atoms
6.022 ×1023 atoms/mol
Amount of substance (in moles) =3.50 ×1023
6.022 ×1023 moles
Amount of substance (in moles) = 0.581 moles
Therefore, the amount of substance in moles present in the sample
containing 3.50 ×1023 atoms of silver is 0.581 moles.Question 16:
Calculate the amount of substance in moles present in a sam-
ple containing 3.50 ×1023 atoms of silver. (Atomic mass of silver =
107.87 g/mol)
Step-by-step solution:
Given: Number of atoms of silver = 3.50 ×1023 Atomic mass of
silver = 107.87 g/mol
12
To calculate the amount of substance in moles, we can use the
following formula:
Amount of substance (in moles) =Number of atoms
Avogadro’s number
First, we need to convert the number of atoms to moles using
Avogadro’s number:
Amount of substance (in moles) =3.50 ×1023 atoms
6.022 ×1023 atoms/mol
Amount of substance (in moles) =3.50 ×1023
6.022 ×1023 moles
Amount of substance (in moles) = 0.581 moles
Therefore, the amount of substance in moles present in the sample
containing 3.50 ×1023 atoms of silver is 0.581 moles.
Question 17
Step-by-step Solution: Given: Number of particles = 1.8×1023
We know that 1 mole of any substance contains Avogadro’s number
of particles, which is 6.022 ×1023 particles.
To calculate the amount of substance in moles, we can use the
following formula:
Amount of substance (moles) =Number of particles
6.022 ×1023
Plugging in the given values:
Amount of substance (moles) =1.8×1023
6.022 ×1023
Amount of substance (moles) = 0.299 moles
Therefore, the amount of substance in moles when 1.8×1023 parti-
cles are present is 0.299 moles.Question 17: Calculate the amount of
substance in moles when 1.8
Ö
1023particlesofasubstancearepresent.
Step-by-step Solution: Given: Number of particles = 1.8×1023
We know that 1 mole of any substance contains Avogadro’s number
of particles, which is 6.022 ×1023 particles.
To calculate the amount of substance in moles, we can use the
following formula:
Amount of substance (moles) =Number of particles
6.022 ×1023
13
Plugging in the given values:
Amount of substance (moles) =1.8×1023
6.022 ×1023
Amount of substance (moles) = 0.299 moles
Therefore, the amount of substance in moles when 1.8×1023 par-
ticles are present is 0.299 moles.
Question 18
Calculate the amount of substance in moles when given the fol-
lowing information:
Mass of the substance = 48.5 g Molar mass of the substance = 32
g/mol
Step-by-step solution:
1. Write down the given values: Mass of the substance = 48.5 g
Molar mass of the substance = 32 g/mol
2. Use the formula to calculate the amount of substance in moles:
Amount of substance (moles) = Mass / Molar mass
3. Substitute the given values into the formula: Amount of sub-
stance (moles) = 48.5 g / 32 g/mol
4. Perform the division to find the amount of substance in moles:
Amount of substance (moles) = 1.515 moles
Therefore, the amount of substance in moles is 1.515 moles.Question
18:
Calculate the amount of substance in moles when given the fol-
lowing information:
Mass of the substance = 48.5 g Molar mass of the substance = 32
g/mol
Step-by-step solution:
1. Write down the given values: Mass of the substance = 48.5 g
Molar mass of the substance = 32 g/mol
2. Use the formula to calculate the amount of substance in moles:
Amount of substance (moles) = Mass / Molar mass
3. Substitute the given values into the formula: Amount of sub-
stance (moles) = 48.5 g / 32 g/mol
4. Perform the division to find the amount of substance in moles:
Amount of substance (moles) = 1.515 moles
Therefore, the amount of substance in moles is 1.515 moles.
Question 19
Question 19: Calculate the amount of substance in moles present
in 3.0 grams of oxygen gas, O2.
14
Solution: Given: Mass of oxygen gas, O2= 3.0 grams Molar mass
of O2= 32 g/mol (Oxygen has a molar mass of 16 g/mol, and since
there are two oxygen atoms in O2, the molar mass of O2is 2 * 16 =
32 g/mol)
To find the amount of substance in moles, we can use the formula:
Amount of substance (in moles) =Mass
Molar mass
Substitute the given values into the formula:
Amount of substance (in moles) =3.0grams
32 g/mol
Amount of substance (in moles) = 0.09375 moles
Therefore, the amount of substance in moles present in 3.0 grams
of oxygen gas, O2, is 0.09375 moles.Certainly! Here is a question along
with its step-by-step solution on Amount of Substance, in LateX code,
for Liberty University.
Question 19: Calculate the amount of substance in moles present
in 3.0 grams of oxygen gas, O2.
Solution: Given: Mass of oxygen gas, O2= 3.0 grams Molar mass
of O2= 32 g/mol (Oxygen has a molar mass of 16 g/mol, and since
there are two oxygen atoms in O2, the molar mass of O2is 2 * 16 =
32 g/mol)
To find the amount of substance in moles, we can use the formula:
Amount of substance (in moles) =Mass
Molar mass
Substitute the given values into the formula:
Amount of substance (in moles) =3.0grams
32 g/mol
Amount of substance (in moles) = 0.09375 moles
Therefore, the amount of substance in moles present in 3.0 grams
of oxygen gas, O2, is 0.09375 moles.
Question 20
Given that the molar mass of carbon is 12 g/mol, determine the
amount of substance in moles of 36 g of carbon.
Step-by-step solution:
1. Determine the number of moles using the formula:
Amount of substance (in moles) =Mass (in grams)
Molar mass (in g/mol)
15
Therefore, 3.50 grams of sodium chloride (NaCl) is approximately
equivalent to 0.06 moles.
Question 3
Calculate the amount of substance in moles if the mass of a sample
is 45 grams and the molar mass of the substance is 3.5 g/mol.
Step-by-step solution:
Given: Mass of the sample = 45 grams Molar mass of the sub-
stance = 3.5 g/mol
The amount of substance (in moles) can be calculated using the
formula:
Amount of substance (moles) =Mass (g)
Molar mass (g/mol)
Substitute the given values into the formula:
Amount of substance (moles) =45 g
3.5g/mol
Amount of substance (moles) =45
3.5
Amount of substance (moles) = 12.86 moles
Therefore, the amount of substance in moles is 12.86 moles.Question
3:
Calculate the amount of substance in moles if the mass of a sample
is 45 grams and the molar mass of the substance is 3.5 g/mol.
Step-by-step solution:
Given: Mass of the sample = 45 grams Molar mass of the sub-
stance = 3.5 g/mol
The amount of substance (in moles) can be calculated using the
formula:
Amount of substance (moles) =Mass (g)
Molar mass (g/mol)
Substitute the given values into the formula:
Amount of substance (moles) =45 g
3.5g/mol
Amount of substance (moles) =45
3.5
Amount of substance (moles) = 12.86 moles
Therefore, the amount of substance in moles is 12.86 moles.
2
Question 4
A student has a 250 mL solution of 0.5 M sulfuric acid, H2SO4.
Calculate the amount of sulfuric acid in moles present in the solution.
Step-by-step solution: 1. The concentration of sulfuric acid solu-
tion is given as 0.5 M, which means there are 0.5 moles of H2SO4 in
1 liter of solution. 2. Convert the volume of the solution to liters:
250 mL = 0.25 L. 3. Calculate the amount of sulfuric acid in moles
present in the solution using the formula:
Amount of substance (moles) =Volume (liters) ×Concentration (M)
Amount of substance (moles) = 0.25 L×0.5M= 0.125 mol
4. Therefore, there are 0.125 moles of sulfuric acid present in the 250
mL solution.Question 4:
A student has a 250 mL solution of 0.5 M sulfuric acid, H2SO4.
Calculate the amount of sulfuric acid in moles present in the solution.
Step-by-step solution: 1. The concentration of sulfuric acid solu-
tion is given as 0.5 M, which means there are 0.5 moles of H2SO4 in
1 liter of solution. 2. Convert the volume of the solution to liters:
250 mL = 0.25 L. 3. Calculate the amount of sulfuric acid in moles
present in the solution using the formula:
Amount of substance (moles) =Volume (liters) ×Concentration (M)
Amount of substance (moles) = 0.25 L×0.5M= 0.125 mol
4. Therefore, there are 0.125 moles of sulfuric acid present in the 250
mL solution.
Question 5
A sample of oxygen gas has a volume of 3.50 L at 25
°
C and 1.20
atm pressure. Calculate the amount of substance of oxygen gas in
moles.
Given: - Volume of oxygen gas, V= 3.50 L - Temperature, T=
25◦C= 298 K - Pressure, P= 1.20 atm - Universal gas constant, R=
0.0821 L·atm ·K−1·mol−1
Solution:
Step 1: Convert the temperature to Kelvin
T= 25◦C= 298 K
Step 2: Use the ideal gas law equation to calculate the amount of
substance (moles)
P V =nRT
3
n=P V
RT
n=(1.20 atm)(3.50 L)
(0.0821 L·atm ·K−1·mol−1)(298 K)
Step 3: Calculate the amount of substance (moles)
n=4.2
24.5058
n= 0.171 mol
Answer: The amount of substance of oxygen gas in the sample is
0.171 moles.Question 5:
A sample of oxygen gas has a volume of 3.50 L at 25
°
C and 1.20
atm pressure. Calculate the amount of substance of oxygen gas in
moles.
Given: - Volume of oxygen gas, V= 3.50 L - Temperature, T=
25◦C= 298 K - Pressure, P= 1.20 atm - Universal gas constant, R=
0.0821 L·atm ·K−1·mol−1
Solution:
Step 1: Convert the temperature to Kelvin
T= 25◦C= 298 K
Step 2: Use the ideal gas law equation to calculate the amount of
substance (moles)
P V =nRT
n=P V
RT
n=(1.20 atm)(3.50 L)
(0.0821 L·atm ·K−1·mol−1)(298 K)
Step 3: Calculate the amount of substance (moles)
n=4.2
24.5058
n= 0.171 mol
Answer: The amount of substance of oxygen gas in the sample is
0.171 moles.
4
Question 6
Calculate the amount of substance in moles of 2.5 grams of oxygen
gas (O2).
Step-by-step solution: 1. Determine the molar mass of oxygen gas
(O2). The molar mass of O2is 2×molar mass of oxygen. The molar
mass of oxygen (O) = 16.00 g/mol The molar mass of O2=2×16.00
= 32.00 g/mol
2. Convert the given mass of oxygen gas (O2) from grams to moles
using the molar mass: Number of moles = mass in grams
molar mass Number of
moles = 2.5g
32.00 g/mol Number of moles ≈0.0781 mol
Therefore, the amount of substance in moles of 2.5 grams of oxygen
gas (O2) is approximately 0.0781 moles.Question 6:
Calculate the amount of substance in moles of 2.5 grams of oxygen
gas (O2).
Step-by-step solution: 1. Determine the molar mass of oxygen gas
(O2). The molar mass of O2is 2×molar mass of oxygen. The molar
mass of oxygen (O) = 16.00 g/mol The molar mass of O2=2×16.00
= 32.00 g/mol
2. Convert the given mass of oxygen gas (O2) from grams to moles
using the molar mass: Number of moles = mass in grams
molar mass Number of
moles = 2.5g
32.00 g/mol Number of moles ≈0.0781 mol
Therefore, the amount of substance in moles of 2.5 grams of oxygen
gas (O2) is approximately 0.0781 moles.
Question 7
Step-by-step Solution: Given: 2.5 moles of carbon dioxide molecules,
CO2Molar mass of carbon dioxide, CO2: 44.01 g/mol
1. Determine the molar relationship between moles and molecules:
1 mole of any substance contains Avogadro’s number of molecules,
which is approximately 6.022 ×1023 molecules.
2. Calculate the number of molecules in 2.5 moles of carbon diox-
ide: Number of molecules = 2.5 moles ×Avogadro’s number Number
of molecules = 2.5 moles ×6.022 ×1023 molecules/mole
3. Calculate the amount of substance in moles of 2.5 moles of
carbon dioxide: Amount of substance (moles) = Mass / Molar mass
Amount of substance (moles) = 2.5 moles
Therefore, the amount of substance in moles of 2.5 moles of car-
bon dioxide molecules, CO2, is 2.5 moles.Question 7: Calculate the
amount of substance in moles of 2.5 moles of carbon dioxide molecules,
CO2.
Step-by-step Solution: Given: 2.5 moles of carbon dioxide molecules,
CO2Molar mass of carbon dioxide, CO2: 44.01 g/mol
5
1. Determine the molar relationship between moles and molecules:
1 mole of any substance contains Avogadro’s number of molecules,
which is approximately 6.022 ×1023 molecules.
2. Calculate the number of molecules in 2.5 moles of carbon diox-
ide: Number of molecules = 2.5 moles ×Avogadro’s number Number
of molecules = 2.5 moles ×6.022 ×1023 molecules/mole
3. Calculate the amount of substance in moles of 2.5 moles of
carbon dioxide: Amount of substance (moles) = Mass / Molar mass
Amount of substance (moles) = 2.5 moles
Therefore, the amount of substance in moles of 2.5 moles of carbon
dioxide molecules, CO2, is 2.5 moles.
Question 8
Calculate the amount of substance in moles for a sample containing
3.2×1023 atoms of sodium.
Step-by-step solution:
Given: Number of atoms of sodium = 3.2×1023
Avogadro’s number, NA= 6.022 ×1023 atoms/mol
1. Calculate the amount of substance in moles using the formula:
Amount of substance (moles) =Number of atoms
Avogadro’s number
Amount of substance (moles) =3.2×1023
6.022 ×1023
Amount of substance (moles) = 0.532 mol
Therefore, the amount of substance in moles for a sample contain-
ing 3.2×1023 atoms of sodium is 0.532 mol.Question 8:
Calculate the amount of substance in moles for a sample containing
3.2×1023 atoms of sodium.
Step-by-step solution:
Given: Number of atoms of sodium = 3.2×1023
Avogadro’s number, NA= 6.022 ×1023 atoms/mol
1. Calculate the amount of substance in moles using the formula:
Amount of substance (moles) =Number of atoms
Avogadro’s number
Amount of substance (moles) =3.2×1023
6.022 ×1023
Amount of substance (moles) = 0.532 mol
Therefore, the amount of substance in moles for a sample contain-
ing 3.2×1023 atoms of sodium is 0.532 mol.
6
Question 9
Step-by-step Solution: Given: Mass of sodium hydroxide (NaOH)
= 3.5 grams Molar mass of NaOH = 22.99 g/mol (for Na) + 16.00
g/mol (for O) + 1.01 g/mol (for H) = 40.00 g/mol
1. Use the formula to calculate moles:
Amount of substance (moles) =Given mass
Molar mass
2. Substitute the given values into the formula:
Amount of substance (moles) =3.5g
40.00 g/mol
3. Calculate the amount of substance in moles:
Amount of substance (moles) =3.5
40.00 = 0.0875 moles
Therefore, the amount of substance in moles when given 3.5 grams
of sodium hydroxide is 0.0875 moles.Question 9: Calculate the amount
of substance in moles when given 3.5 grams of sodium hydroxide
(NaOH).
Step-by-step Solution: Given: Mass of sodium hydroxide (NaOH)
= 3.5 grams Molar mass of NaOH = 22.99 g/mol (for Na) + 16.00
g/mol (for O) + 1.01 g/mol (for H) = 40.00 g/mol
1. Use the formula to calculate moles:
Amount of substance (moles) =Given mass
Molar mass
2. Substitute the given values into the formula:
Amount of substance (moles) =3.5g
40.00 g/mol
3. Calculate the amount of substance in moles:
Amount of substance (moles) =3.5
40.00 = 0.0875 moles
Therefore, the amount of substance in moles when given 3.5 grams
of sodium hydroxide is 0.0875 moles.
Question 10
Calculate the amount of substance in moles in 2.5 grams of carbon
dioxide (CO2).
Step-by-step solution:
7
1. Determine the molar mass of carbon dioxide (CO2): The molar
mass of C= 12.01 g/mol. The molar mass of O= 16.00 g/mol.
Molar mass of CO2= (12.01×1)+(16.00×2) = 12.01+32.00 = 44.01 g/mol.
2. Calculate the number of moles: Given mass = 2.5 grams.
Number of moles =Given mass
Molar mass =2.5
44.01 ≈0.0569 moles.
Therefore, the amount of substance in 2.5 grams of carbon dioxide
is approximately 0.0569 moles.Question 10:
Calculate the amount of substance in moles in 2.5 grams of carbon
dioxide (CO2).
Step-by-step solution:
1. Determine the molar mass of carbon dioxide (CO2): The molar
mass of C= 12.01 g/mol. The molar mass of O= 16.00 g/mol.
Molar mass of CO2= (12.01×1)+(16.00×2) = 12.01+32.00 = 44.01 g/mol.
2. Calculate the number of moles: Given mass = 2.5 grams.
Number of moles =Given mass
Molar mass =2.5
44.01 ≈0.0569 moles.
Therefore, the amount of substance in 2.5 grams of carbon dioxide
is approximately 0.0569 moles.
Question 11
Calculate the number of moles in 2.5 grams of potassium hydroxide
(KOH).
Step-by-step Solution:
Given: Mass of potassium hydroxide (KOH) = 2.5 grams
1. Determine the molar mass of potassium hydroxide (KOH):
Molar mass of KOH = atomic mass of K + atomic mass of O +
atomic mass of H Molar mass of KOH = 39.10 g/mol + 16.00 g/mol
+ 1.01 g/mol Molar mass of KOH = 56.11 g/mol
2. Use the formula to calculate the number of moles: Number of
moles = Mass / Molar mass Number of moles = 2.5 grams / 56.11
g/mol Number of moles 0.0446 moles
Therefore, there are approximately 0.0446 moles in 2.5 grams of
potassium hydroxide (KOH).Question 11:
Calculate the number of moles in 2.5 grams of potassium hydroxide
(KOH).
Step-by-step Solution:
Given: Mass of potassium hydroxide (KOH) = 2.5 grams
1. Determine the molar mass of potassium hydroxide (KOH):
Molar mass of KOH = atomic mass of K + atomic mass of O +
atomic mass of H Molar mass of KOH = 39.10 g/mol + 16.00 g/mol
+ 1.01 g/mol Molar mass of KOH = 56.11 g/mol
2. Use the formula to calculate the number of moles: Number of
moles = Mass / Molar mass Number of moles = 2.5 grams / 56.11
g/mol Number of moles 0.0446 moles
8
Therefore, there are approximately 0.0446 moles in 2.5 grams of
potassium hydroxide (KOH).
Question 12
Step-by-step solution: 1. Write down the given information: -
Mass of iron: 10.0 g - Amount of iron atoms: 0.179 mol
2. Calculate the molar mass using the formula:
Molar mass =Mass
Amount of substance
3. Substitute the values into the formula:
Molar mass =10.0g
0.179 mol
4. Perform the division to find the molar mass:
Molar mass =10.0
0.179 ≈55.87 g/mol
Therefore, the molar mass of iron is approximately 55.87 g/mol.Question
12: A sample of iron with a mass of 10.0 g contains 0.179 mol of iron
atoms. Calculate the molar mass of iron.
Step-by-step solution: 1. Write down the given information: -
Mass of iron: 10.0 g - Amount of iron atoms: 0.179 mol
2. Calculate the molar mass using the formula:
Molar mass =Mass
Amount of substance
3. Substitute the values into the formula:
Molar mass =10.0g
0.179 mol
4. Perform the division to find the molar mass:
Molar mass =10.0
0.179 ≈55.87 g/mol
Therefore, the molar mass of iron is approximately 55.87 g/mol.
Question 13
Calculate the amount of substance in moles when given the fol-
lowing mass of a substance:
Mass of substance = 25.6 grams Molar mass of the substance =
32.0 g/mol
9
Step-by-step Solution:
1. Write down the given information: Mass of substance = 25.6
grams Molar mass of the substance = 32.0 g/mol
2. Use the formula to calculate the amount of substance in moles:
Amount of substance (moles) = Mass of substance / Molar mass
3. Substitute the given values into the formula: Amount of sub-
stance (moles) = 25.6 g / 32.0 g/mol
4. Calculate the amount of substance in moles: Amount of sub-
stance (moles) = 0.8 moles
Therefore, the amount of substance in moles is 0.8 moles.Question
13:
Calculate the amount of substance in moles when given the fol-
lowing mass of a substance:
Mass of substance = 25.6 grams Molar mass of the substance =
32.0 g/mol
Step-by-step Solution:
1. Write down the given information: Mass of substance = 25.6
grams Molar mass of the substance = 32.0 g/mol
2. Use the formula to calculate the amount of substance in moles:
Amount of substance (moles) = Mass of substance / Molar mass
3. Substitute the given values into the formula: Amount of sub-
stance (moles) = 25.6 g / 32.0 g/mol
4. Calculate the amount of substance in moles: Amount of sub-
stance (moles) = 0.8 moles
Therefore, the amount of substance in moles is 0.8 moles.
Question 14
Step-by-step solution: To calculate the amount of substance in
moles, we can use Avogadro’s number, which is 6.02 ×1023 mol−1.
Given that we have 6.02×1023 atoms of carbon, we can directly convert
this to moles by dividing by Avogadro’s number:
Amount of substance (moles) =6.02 ×1023 atoms
6.02 ×1023 mol−1
Amount of substance (moles) = 1 mol
Therefore, the amount of substance in 6.02
Ö
10
²³
atoms of carbon
is 1 mole.Question 14: Calculate the amount of substance in moles in
6.02
Ö
10
²³
atoms of carbon.
Step-by-step solution: To calculate the amount of substance in
moles, we can use Avogadro’s number, which is 6.02 ×1023 mol−1.
Given that we have 6.02×1023 atoms of carbon, we can directly convert
this to moles by dividing by Avogadro’s number:
10
Amount of substance (moles) =6.02 ×1023 atoms
6.02 ×1023 mol−1
Amount of substance (moles) = 1 mol
Therefore, the amount of substance in 6.02
Ö
10
²³
atoms of carbon
is 1 mole.
Question 15
Step-by-step solution: 1. Determine the molar mass of calcium
carbonate (CaCO):
Ca : 40.08 g/mol
C: 12.01 g/mol
O: 16.00 g/mol
Adding these molar masses:
40.08 + 12.01 + (16.00 ×3) = 100.09 g/mol
2. Calculate the number of moles using the formula:
Amount of substance (moles) =Mass (g)
Molar mass (g/mol)
Substitute the given values:
Amount of substance (moles) =3.5g
100.09 g/mol
Amount of substance (moles) = 0.035 mol
Therefore, the amount of substance in moles for 3.5 grams of cal-
cium carbonate is 0.035 moles.Question 15: Calculate the amount of
substance in moles if 3.5 grams of calcium carbonate (CaCO) is given.
Step-by-step solution: 1. Determine the molar mass of calcium
carbonate (CaCO):
Ca : 40.08 g/mol
C: 12.01 g/mol
O: 16.00 g/mol
Adding these molar masses:
40.08 + 12.01 + (16.00 ×3) = 100.09 g/mol
11
2. Calculate the number of moles using the formula:
Amount of substance (moles) =Mass (g)
Molar mass (g/mol)
Substitute the given values:
Amount of substance (moles) =3.5g
100.09 g/mol
Amount of substance (moles) = 0.035 mol
Therefore, the amount of substance in moles for 3.5 grams of cal-
cium carbonate is 0.035 moles.
Question 16
Calculate the amount of substance in moles present in a sam-
ple containing 3.50 ×1023 atoms of silver. (Atomic mass of silver =
107.87 g/mol)
Step-by-step solution:
Given: Number of atoms of silver = 3.50 ×1023 Atomic mass of
silver = 107.87 g/mol
To calculate the amount of substance in moles, we can use the
following formula:
Amount of substance (in moles) =Number of atoms
Avogadro’s number
First, we need to convert the number of atoms to moles using
Avogadro’s number:
Amount of substance (in moles) =3.50 ×1023 atoms
6.022 ×1023 atoms/mol
Amount of substance (in moles) =3.50 ×1023
6.022 ×1023 moles
Amount of substance (in moles) = 0.581 moles
Therefore, the amount of substance in moles present in the sample
containing 3.50 ×1023 atoms of silver is 0.581 moles.Question 16:
Calculate the amount of substance in moles present in a sam-
ple containing 3.50 ×1023 atoms of silver. (Atomic mass of silver =
107.87 g/mol)
Step-by-step solution:
Given: Number of atoms of silver = 3.50 ×1023 Atomic mass of
silver = 107.87 g/mol
12
To calculate the amount of substance in moles, we can use the
following formula:
Amount of substance (in moles) =Number of atoms
Avogadro’s number
First, we need to convert the number of atoms to moles using
Avogadro’s number:
Amount of substance (in moles) =3.50 ×1023 atoms
6.022 ×1023 atoms/mol
Amount of substance (in moles) =3.50 ×1023
6.022 ×1023 moles
Amount of substance (in moles) = 0.581 moles
Therefore, the amount of substance in moles present in the sample
containing 3.50 ×1023 atoms of silver is 0.581 moles.
Question 17
Step-by-step Solution: Given: Number of particles = 1.8×1023
We know that 1 mole of any substance contains Avogadro’s number
of particles, which is 6.022 ×1023 particles.
To calculate the amount of substance in moles, we can use the
following formula:
Amount of substance (moles) =Number of particles
6.022 ×1023
Plugging in the given values:
Amount of substance (moles) =1.8×1023
6.022 ×1023
Amount of substance (moles) = 0.299 moles
Therefore, the amount of substance in moles when 1.8×1023 parti-
cles are present is 0.299 moles.Question 17: Calculate the amount of
substance in moles when 1.8
Ö
1023particlesofasubstancearepresent.
Step-by-step Solution: Given: Number of particles = 1.8×1023
We know that 1 mole of any substance contains Avogadro’s number
of particles, which is 6.022 ×1023 particles.
To calculate the amount of substance in moles, we can use the
following formula:
Amount of substance (moles) =Number of particles
6.022 ×1023
13
Plugging in the given values:
Amount of substance (moles) =1.8×1023
6.022 ×1023
Amount of substance (moles) = 0.299 moles
Therefore, the amount of substance in moles when 1.8×1023 par-
ticles are present is 0.299 moles.
Question 18
Calculate the amount of substance in moles when given the fol-
lowing information:
Mass of the substance = 48.5 g Molar mass of the substance = 32
g/mol
Step-by-step solution:
1. Write down the given values: Mass of the substance = 48.5 g
Molar mass of the substance = 32 g/mol
2. Use the formula to calculate the amount of substance in moles:
Amount of substance (moles) = Mass / Molar mass
3. Substitute the given values into the formula: Amount of sub-
stance (moles) = 48.5 g / 32 g/mol
4. Perform the division to find the amount of substance in moles:
Amount of substance (moles) = 1.515 moles
Therefore, the amount of substance in moles is 1.515 moles.Question
18:
Calculate the amount of substance in moles when given the fol-
lowing information:
Mass of the substance = 48.5 g Molar mass of the substance = 32
g/mol
Step-by-step solution:
1. Write down the given values: Mass of the substance = 48.5 g
Molar mass of the substance = 32 g/mol
2. Use the formula to calculate the amount of substance in moles:
Amount of substance (moles) = Mass / Molar mass
3. Substitute the given values into the formula: Amount of sub-
stance (moles) = 48.5 g / 32 g/mol
4. Perform the division to find the amount of substance in moles:
Amount of substance (moles) = 1.515 moles
Therefore, the amount of substance in moles is 1.515 moles.
Question 19
Question 19: Calculate the amount of substance in moles present
in 3.0 grams of oxygen gas, O2.
14
Solution: Given: Mass of oxygen gas, O2= 3.0 grams Molar mass
of O2= 32 g/mol (Oxygen has a molar mass of 16 g/mol, and since
there are two oxygen atoms in O2, the molar mass of O2is 2 * 16 =
32 g/mol)
To find the amount of substance in moles, we can use the formula:
Amount of substance (in moles) =Mass
Molar mass
Substitute the given values into the formula:
Amount of substance (in moles) =3.0grams
32 g/mol
Amount of substance (in moles) = 0.09375 moles
Therefore, the amount of substance in moles present in 3.0 grams
of oxygen gas, O2, is 0.09375 moles.Certainly! Here is a question along
with its step-by-step solution on Amount of Substance, in LateX code,
for Liberty University.
Question 19: Calculate the amount of substance in moles present
in 3.0 grams of oxygen gas, O2.
Solution: Given: Mass of oxygen gas, O2= 3.0 grams Molar mass
of O2= 32 g/mol (Oxygen has a molar mass of 16 g/mol, and since
there are two oxygen atoms in O2, the molar mass of O2is 2 * 16 =
32 g/mol)
To find the amount of substance in moles, we can use the formula:
Amount of substance (in moles) =Mass
Molar mass
Substitute the given values into the formula:
Amount of substance (in moles) =3.0grams
32 g/mol
Amount of substance (in moles) = 0.09375 moles
Therefore, the amount of substance in moles present in 3.0 grams
of oxygen gas, O2, is 0.09375 moles.
Question 20
Given that the molar mass of carbon is 12 g/mol, determine the
amount of substance in moles of 36 g of carbon.
Step-by-step solution:
1. Determine the number of moles using the formula:
Amount of substance (in moles) =Mass (in grams)
Molar mass (in g/mol)
15
