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Q-40 WORKSHEET 3 NAME 1a. In the first step of procedure 1 ammonia is added. Iro

ID: 491178 • Letter: Q

Question

Q-40 WORKSHEET 3 NAME 1a. In the first step of procedure 1 ammonia is added. Iron(Ill) hydroxide and aluminum hydroxide precipitate from solution as a result write a balanced NIE that corresponds to the precipitation of iron(Ill) hydroxide in aqueous ammonia. (Hint: this equation is analogous to the precipitation of bismuth hydroxide from aqueous ammonia: worksheet 2, 5b.) b. The group Ill cations are precipitated from solution as metal sulfides. The source of sulfide is ammonium sulfide. Is ammonium sulfide an electrolyte or non-electrolyte in water? c. Write a balanced NIE that corresponds to the dissolution of ammonium sulfide. d. Write a balanced NIE that corresponds to the precipitation of manganese(ll) sulfide in procedure ill-1. 2a. Iron(ll) sulfide, manganese(Ill sulfide, and zinc sulfide dissolve in nitric acid (procedure due to the oxidation of sulfide to elemental sulfur. Write balanced NIE that corresponds to the dissolution of nitric acid. (Hint This equation is analogous to the dissolution of lead sulfide worksheet 2, 2.) by reaction with aqueous sodium hydroxide in procedure lll-2. (Hint: is sodium hydroxide a strong or weak base?) c, write a balanced NIE that corresponds to the formation of the complex ion iznoH) F- by the reaction of zinc ion with excess sodium hydroxide in procedure ill 2.

Explanation / Answer

1a. Precipitation of Fe(OH)3

Fe3+(aq) + 3NH4OH(aq) ---> Fe(OH)3(s) + 3NH4+(aq)

b. NH4S is an electrolyte in water

c. NH4S(s) ---> NH4+(aq) + S^2-(sq)

d. Mn2+(aq) + S^2- --> MnS(s)

2a. MnS + 8HNO3 --> MnSO4 + 8NO2 + 4H2O

b. Mn2+(aq) + 2OH-(aq) --> Mn(OH)2(s)

c. Zn2+(aq) + 4OH-(aq) ---> [Zn(OH)4]2-

3a. Mn(OH)2(s) + 2HNO3(aq) --> Mn(NO3)2(aq) + 2H2O(l)

b. 2Mn2+ --> 2MnO4^-

5BiO3- --> 5Bi3+

4a. [Zn(OH)4]2- + 4HNO3 --> Zn(NO3)2 + 4H2O + 2NO3-

b. Zn2+ + 4NH3 ---> [Zn(NH3)4]2+

c. 3Zn2+ + 2K4[Fe(CN)6] --> K2Zn3[Fe(CN)6]2 + 6K+