##### Exam 2B Spring 2005

March 11, 2005

Possibly useful information:

 pH = –log[ H3O+ ] pOH = –log[ OH– ] pH + pOH = 14.00 at 25 oC log(1.0×10–3) = –3 log(1.0×10–4) = –4 log(2.0×10–3) = –2.698970004 log(2.0×10–4) = –3.696870004 log(3.0×10–3) = –2.522878745 log(3.0×10–4) = –3.522878745 log(4.0×10–3) = –2.397940009 log(4.0×10–4) = –3.397940009 log(5.0×10–3) = –2.301029996 log(5.0×10–4) = –3.301029996 log(6.0×10–3) = –2.22184875 log(6.0×10–4) = –3.22184875 log(7.0×10–3) = –2.15490196 log(7.0×10–4) = –3.15490196 log(8.0×10–3) = –2.096910013 log(8.0×10–4) = –3.096910013 log(9.0×10–3) = –2.045757491 log(9.0×10–4) = –3.045757491

1. Complete and balance the following reactions:

a. H3PO4(aq) + CsOH(aq)

b. C6H5NH2(aq) + HBr(aq)

c. HClO2(aq) + H2O(l)

d. Ba(OH)2(s) + HClO4(aq)

2. Complete and balance the following reaction and identify the acid, the base, the conjugate acid, and the conjugate base:

bicarbonate ion + cyanide ion

3. Identify the Lewis acid and the Lewis base in the following reaction.

Cd2+(aq) + 4 NH3(aq) [Cd(NH3)4]2+(aq)

4. Identify the stronger acid in pair given below. Briefly (5 words or less) justify your reasoning.

a. H2Se or H2Te

b. H2SO3 or H2SeO3

5. Calculate the pH and pOH of the following solutions:

a. 2.0×10–4 M hydrobromic acid.

b. 3.0×10–4 M lithium hydroxide.

c. 4.0×10–4 M calcium hydroxide.

6. Consider the reaction shown below, which has H = 131 kJ/mol.

C(s) + H2O(g) CO(g) + H2(g)

a. Which way will the reaction shift if graphite(solid carbon) is added to the reaction? Explain.

b. Which way will the reaction shift if the temperature is raised? Explain.

7. Estimate the pH of a 1.0×10–2 M solution of phenol, C6H5OH. Show all the steps needed to solve the problem until you are required to do algebra. Then make a chemically reasonable estimate of the pH. Ka = 1.0×10–10