Homework Solutions
Chapter 4: 19, 21, 23, 33, 39, 41, 43, 53, 55, 57, 59, 63, 65, 73, 77, 93, 109
19. By the rules given in Table 4.2:
a. Ca3(PO4)2 insoluble
b. Mn(OH)2 insoluble
c. AgClO3 soluble
d. K2S soluble
21. a. Complete ionic equation:
2 Ag+(aq) + 2 NO3–(aq) + 2 Na+(aq) + SO42–(aq) Ag2SO4(s) + 2 Na+(aq) + 2 NO3–(aq)
Net ionic equation: 2 Ag+(aq) + SO42-(aq) Ag2SO4(s)
b. Complete ionic equation:
Ba2+(aq) +2 Cl–(aq) + Zn2+(aq) + SO42-(aq) BaSO4(s) + Zn2+(aq) + 2 Cl–(aq)
Net ionic equation: Ba2+(aq) + SO42–(aq) BaSO4(s)
c. Complete ionic equation:
2 NH4+(aq) + CO32–(aq) + Ca2+(aq) + 2 Cl–(aq) CaCO3(s) + 2 NH4+(aq) + 2 Cl–(aq)
Net ionic equation: Ca2+(aq) + CO32–(aq) CaCO3(s)
23. To determine if a reaction will occur, you must predict the possible products and
determine their solubility:
a. 2 NaNO3(aq) + CuSO4(aq) Na2SO4(aq) + Cu(NO3)2(aq) no precipitate formed
b. BaCl2(aq) + K2SO4(aq) BaSO4(s) +2 KCl(aq) barium sulfate is precipitate
Net ionic reaction for this process: Ba2+(aq) + SO42–(aq) BaSO4(s)
, Homework Solutions
33. Remember, strong acids and bases are also strong electrolytes and are completely ionized.
a. Complete ionic equation: H+(aq) + Br–(aq) + NH3(aq) NH4+(aq) + Br–(aq)
Net ionic equation: H+(aq) + NH3(aq) NH4+(aq)
b. Complete ionic equation:
3 Ba2+(aq) + 6 OH–(aq) + 2 H3PO4(aq) Ba3(PO4)2(s) + 6 H2O(ℓ)
Net ionic equation:
3 Ba2+(aq) + 6 OH–(aq) + 2 H3PO4(aq) Ba3(PO4)2(s) + 6 H2O(ℓ)
c. Complete ionic equation:
2 H+(aq) + 2 ClO4–(aq) + Mg(OH)2(s) Mg2+(aq) + 2 ClO4–(aq) + 2 H2O(ℓ)
Net ionic equation: 2 H+(aq) + Mg(OH)2(s) Mg2+(aq) + 2 H2O(ℓ)
39. Note-you may or may not be asked to determine half-reactions(HR) - talk to your instructor.
a. 2 Sr(s) + O2(g) 2 SrO(s)
Oxidation HR : 2 Sr 2 Sr2+ + 4e– Reduction HR: O2 + 4e– 2 O2–
Sr is oxidized, it is also the reducing agent O is reduced, O2 is the oxidizing agent
b. 2 Li(s) + H2(g) 2 LiH(s)
Oxidation HR: 2 Li 2 Li+ + 2e– Reduction HR: H2 + 2e– 2 H–
Li is oxidized, it is also the reducing agent H is reduced, H2 is the oxidizing agent
c. 2 Cs + Br2 2 CsBr
Oxidation HR: 2 Cs 2 Cs+ + 2e– Reduction HR: Br2 + 2e– 2 Br-
Cs is oxidized, it is also the reducing agent Br is reduced, Br2 is the oxidizing agent
d. 3 Mg + N2 Mg3N2
Oxidation HR: 3 Mg 3 Mg2+ + 6e– Reduction HR: N2 + 6e– 2 N3–
Mg is oxidized, it is also the reducing agent N is reduced, N2 is the oxidizing agent
Chapter 4: 19, 21, 23, 33, 39, 41, 43, 53, 55, 57, 59, 63, 65, 73, 77, 93, 109
19. By the rules given in Table 4.2:
a. Ca3(PO4)2 insoluble
b. Mn(OH)2 insoluble
c. AgClO3 soluble
d. K2S soluble
21. a. Complete ionic equation:
2 Ag+(aq) + 2 NO3–(aq) + 2 Na+(aq) + SO42–(aq) Ag2SO4(s) + 2 Na+(aq) + 2 NO3–(aq)
Net ionic equation: 2 Ag+(aq) + SO42-(aq) Ag2SO4(s)
b. Complete ionic equation:
Ba2+(aq) +2 Cl–(aq) + Zn2+(aq) + SO42-(aq) BaSO4(s) + Zn2+(aq) + 2 Cl–(aq)
Net ionic equation: Ba2+(aq) + SO42–(aq) BaSO4(s)
c. Complete ionic equation:
2 NH4+(aq) + CO32–(aq) + Ca2+(aq) + 2 Cl–(aq) CaCO3(s) + 2 NH4+(aq) + 2 Cl–(aq)
Net ionic equation: Ca2+(aq) + CO32–(aq) CaCO3(s)
23. To determine if a reaction will occur, you must predict the possible products and
determine their solubility:
a. 2 NaNO3(aq) + CuSO4(aq) Na2SO4(aq) + Cu(NO3)2(aq) no precipitate formed
b. BaCl2(aq) + K2SO4(aq) BaSO4(s) +2 KCl(aq) barium sulfate is precipitate
Net ionic reaction for this process: Ba2+(aq) + SO42–(aq) BaSO4(s)
, Homework Solutions
33. Remember, strong acids and bases are also strong electrolytes and are completely ionized.
a. Complete ionic equation: H+(aq) + Br–(aq) + NH3(aq) NH4+(aq) + Br–(aq)
Net ionic equation: H+(aq) + NH3(aq) NH4+(aq)
b. Complete ionic equation:
3 Ba2+(aq) + 6 OH–(aq) + 2 H3PO4(aq) Ba3(PO4)2(s) + 6 H2O(ℓ)
Net ionic equation:
3 Ba2+(aq) + 6 OH–(aq) + 2 H3PO4(aq) Ba3(PO4)2(s) + 6 H2O(ℓ)
c. Complete ionic equation:
2 H+(aq) + 2 ClO4–(aq) + Mg(OH)2(s) Mg2+(aq) + 2 ClO4–(aq) + 2 H2O(ℓ)
Net ionic equation: 2 H+(aq) + Mg(OH)2(s) Mg2+(aq) + 2 H2O(ℓ)
39. Note-you may or may not be asked to determine half-reactions(HR) - talk to your instructor.
a. 2 Sr(s) + O2(g) 2 SrO(s)
Oxidation HR : 2 Sr 2 Sr2+ + 4e– Reduction HR: O2 + 4e– 2 O2–
Sr is oxidized, it is also the reducing agent O is reduced, O2 is the oxidizing agent
b. 2 Li(s) + H2(g) 2 LiH(s)
Oxidation HR: 2 Li 2 Li+ + 2e– Reduction HR: H2 + 2e– 2 H–
Li is oxidized, it is also the reducing agent H is reduced, H2 is the oxidizing agent
c. 2 Cs + Br2 2 CsBr
Oxidation HR: 2 Cs 2 Cs+ + 2e– Reduction HR: Br2 + 2e– 2 Br-
Cs is oxidized, it is also the reducing agent Br is reduced, Br2 is the oxidizing agent
d. 3 Mg + N2 Mg3N2
Oxidation HR: 3 Mg 3 Mg2+ + 6e– Reduction HR: N2 + 6e– 2 N3–
Mg is oxidized, it is also the reducing agent N is reduced, N2 is the oxidizing agent
