Exam 3A, Spring 2002

1. Complete and balance the following reactions.

a. aqueous sulfuric acid plus solid barium hydroxide

b. C₆H₅NH₂(aq) + H₂O(l)

c. C₆H₅NH₂(aq) + HBr(aq)

d. Mg(ClO₄)₂(aq) + NaOH(aq)

e. NaF(aq) + Sc(NO₃)₃(aq)

f. H₂PO₄^–(aq) + HAsO₄^2–(aq)

g. Mn²⁺(aq) + H₂O(l)

2. Find the pH of a 0.0010 M solution of Na₂Se. Write all of the appropriate chemical reactions. K_a for HSe^– = 1.0×10^–11

3. A buffer is prepared to be 0.10 M NaH₂PO₄ and 0.10 M Na₂HPO₄.

a. Find the pH of the buffer at 25 °C. Write all of the appropriate chemical reactions.

b. 0.025 moles of HCl(g) is added to 1.0 L of the buffer. Write any new chemical reactions that occur and find the new pH in the buffer solution.

4. Consider the solubility of lead carbonate.

a. Find the molar solubility in water. Write the appropriate chemical reactions.

b. Find the molar solubility of lead carbonate in a 0.10 M solution of lead nitrate. Write the appropriate chemical reactions.

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