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Exam 2B
Spring 2004

February 27, 2004


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. H2SO4(aq) + KOH(aq)

b. C6H5NH2(aq) + HBr(aq)

c. HOBr(aq) + H2O(l)

d. Mg(OH)2(s) + HNO3(aq)

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

CO32–(aq) + CH3CH2CO2H(aq)

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

Al(OH)3(s) + OH(aq) Al(OH)4(aq)

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

a. H2O or H2S

b. H2SeO4 or H2TeO4

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

a. 2.0×10–4 M perchloric acid.

b. 2.0×10–4 M potassium hydroxide.

c. 3.0×10–4 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 the pressure is decreased by expanding the volume?

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

7. Estimate the pH of a 2.0×10–4 M solution of HNO2. 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 = 7.2×10–4