Exam 3B, Spring 2006

1. Complete and balance the following reactions:

a. H₂SO₄(aq) + KOH(aq)

b. cyanate ion plus water

c. Fe³⁺(aq) + EDTA^4–(aq)

d. FeCl₂(aq) + Na₂CO₃(aq)

e. HCN(aq) + NH₃(aq)

f. Cu²⁺(aq) + H₂O(l)

g. Pb(OH)₂(s) + H₃PO₄(aq)

2. Identify if the following ionic salts are acidic, basic, or neutral in aqueous solution. Show the reaction that defines the acidity or basicity, if the salt is not neutral.

a. NiI₂

b. NaClO₄

c. KNO₂

3. A buffer is prepared to be 0.10 M in HClO₂ and 0.10 M in NaClO₂.

a. Calculate the pH of the solution, showing all of your work.

b. 0.1 g of NaOH(s) is added to 1 L of the buffer. Calculate the new pH.

4. A mixture of Co(OH)₃ in water is prepared. Will the solubility in increase, decrease, or stay the same if the mixture is added to the following solutions. Show a chemical reaction to justify your answer if the solubility increases or decreases.

a. 1 M HNO₃

b. 1 M NaNO₃

c. 1 M NH₃

5. Determine the solubility of ScF₃ in a 0.10 M solution of NaF.

Answers