chemistry

Chapter 4: Reactions in Aqueous Solutions

Homework Assignment

All work and calculations must be shown

Question 1:

Specify which ions are present upon dissolving the following substances in water:

a. MgI2

b. K2CO3

c. HClO4

d. NaCH3COO

Question 2:

Predict whether each of the following compounds are soluble in water:

a. Na2CO3

b. AgI

c. BaCl2

d. Al(OH)3

e. Zn(CH3COO)2

Question 3:

Identify the precipitate (if any) that forms when the following solutions are mixed and write the balanced chemical equation for each reaction.

a. NaCH3COO and HCl

b. KOH and Cu(NO3)2

c. Na2S and CdSO4

Question 4:

Write the balanced net ionic equations for the reactions that occur in each of the following cases. Identify the spectator ions(s) in each reaction.

a. Cr2(SO4)3 ( aq) + (NH4)2CO3 ( aq) →

b. Ba(NO3)2 ( aq) + K2SO4 ( aq) →

c. Fe(NO3)2 ( aq) + KOH ( aq) →

Question 5:

Label each of the following substances as an acid, base, salt, or none of the above. Indicate whether the substance exist in an aqueous solution entirely in its molecular form, entirely as ions, or as a mixture of molecules and ions.

a. HF

b. CH3CN

c. NaClO4

d. Ba(OH)2

Question 6:

Classify each of the following aqueous solutions as a nonelectrolyte, weak electrolyte, or strong electrolyte in water.

a. HClO

b. CH3CH2CH2OH

c. LiClO4

d. HClO3

e. CuSO4

f. C12H22O11

Question 7:

Write the balanced molecular and net ionic equations for each of the following neutralization reactions:

a. CH3COOH ( aq) + Ba(OH)2 ( aq) →

b. Cr(OH)3 ( s) + HNO3 ( aq) →

c. HNO3 ( aq) + NH3 ( aq) →

Question 8:

Indicate if each state below is either True or False:

a. If a substance is oxidized, it gains electrons

b. If an ion is oxidized, its oxidation number increases

c. Oxidation can occur without oxygen

d. Oxidation can occur without reduction

Question 9:

Determine the oxidation number of sulfur in each of the following substances:

a. BaSO4

b. H2SO3

c. H2S

Question 10:

Determine the oxidation number for the indicated element in each of the following compounds:

a. Co in LiCoO2

b. Al in NaAlH4

c. C in CH3OH

d. N in GaN

e. Cl in HClO2

f. Cr in BaCrO4

Question 11:

Which of the following reactions are redox reactions? For those that are, indicate which element is oxidized and which is reduced. For those reactions that are not redox reactions, indicate whether they are precipitation or neutralization reactions.

a. P4 ( s) + 10 HClO ( aq) + 6 H2O ( l) → 4 H3PO4 ( aq) + 10 HCl ( aq)

b. Br2 ( l) + 2 K ( s) → 2 KBr ( s)

c. CH3CH2OH ( l) + 3 O2 ( g) → 3 H2O ( l) + CO2 ( g)

d. ZnCl2 ( aq) + 2 NaOH ( aq) → Zn(OH)2 ( s) + 2 NaCl ( aq)

Question 12:

a. Calculate the molarity of a solution made by dissolving 12.5 g of Na2CrO4 in enough water to make exactly 750 mL of solution.

b. How many moles of KBr are present in 150 mL of a 0.122 M solution?

c. How many milliliters of 6.1 M HCl solution are needed to obtain 0.150 mol of HCl?

Question 13:

In each of the following pairs, indicate which has the higher concentration of I- ions:

a. 0.10 M of BaI2 or 0.25 M KI solution

b. 100 mL of 0.10 M KI solution or 200 mL of 0.040 M of ZnI2 solution?

c. 3.2 M HI solution or a solution made by dissolving 145 g of NaI in water to make a 150 mL solution?

Question 14:

a. How many milliliters of a stock solution of 6.0 M HNO3 would be required to prepare 110 mL of 0.500 M HNO3 solution?

b. IF you dilute 10.0 mL of the stock solution (referenced in part a) to a final volume of 0.250 L, what will be the concentration of the diluted solution?

Question 15:

Refer to the balanced chemical equation:

2 NaHCO3 ( s) + H2SO4 ( aq) → Na2SO4 ( aq) + 2 H2O ( l) + 2 CO2 ( g)

If you spilled sulfuric acid on the benchtop and solid sodium bicarbonate is added until the fizzing, caused by the formation of carbon dioxide, stops. If 35 mL of 5.5 M H2SO4 was spilled, what is the minimum mass of NaHCO3 that must be added to the spill to neutralize the acid?