8.11: End of Chapter Problems
Neutralization Reaction
Write a double replacement reaction of
a. stomach acid with milk of magnesia
b. stomach acid with tums
c. vinegar and egg shell
d. hydrochloric acid and sodium hydroxide.
Acids and Bases
1. Give the formula of the following.
Phosphoric acid
Carbonic acid
Hydroiodic acid
Hydrofluoric acid
potassium hydroxide
Calcium bicarbonate
Barium hydroxide
Lithium carbonate
2. Give the name of the following:
HCl (aq)
HBr (aq)
HNO 3 (aq)
H 2 SO 4 (aq)
NaOH
KHCO 3
Na 2 CO 3
CaCO 3
Bronsted-Lowry Acids and Bases
1. What is the formula and name for the conjugate base of each of the following acids?
H 2 CO 3
H 2 SO 4
HCO 3 -
H 2 PO 4 -
HSO 4 -
HPO 4 2 -
H 3 PO 4
HNO 3
2. What is the formula and name for the conjugate acid of each of the following bases?
F -
NH 3
CN -
NO 2 -
OH -
CH 3 NH 2
Cl -
PO 4 3 -
3. Identify the Bronsted-Lowry acids and bases for the forward and reverse reaction of each.
F - (aq) + HCl(aq) ⇌ HF(aq) + Cl - (aq)
CH 3 CO 2 H(aq) + NO 3 - (aq) ⇌ CH 3 CO 2 - (aq) + HNO 3 (aq)
PO 4 3 - (aq) + NH 4 + (aq) ⇌ NH 3 (aq) + HPO 4 2 - (aq)
HCN(aq) + H 2 PO 4 - (aq) ⇌ CN - (aq) + H 3 PO 4 (aq)
NH 4 + (aq) + SO 4 2 - (aq) ⇌ NH 3 (aq) + HSO 4 2 - (aq)
CN - (aq) + HI(aq) ⇌ HCN(aq) + I - (aq)
OH - (aq) + HNO 3 (aq) ⇌ HOH(l) + NO 3 - (aq)
HPO 4 2 - (aq) + CO 3 2 - (aq) ⇌ PO 4 3 - (aq) + HCO 3 - (aq)
Equilibrium
1. True or False
a. The concentration of the reactants is always equal to the concentration of the products.
b. The reactants are not converted to products.
c. The rate of the forward reaction is equal to the rate of the reverse reaction.
d. The forward and reverse reactions stop.
e. The concentration of the reactants and products does not change.
f. The rate of the forward reaction is greater than the rate of the reverse reaction.
2. Balance the following chemical equations and write the equilibrium constant expression.
CH 4 (g) + H 2 O(g) ⇌ H 2 (g) + CO(g)
H 2 (g) + N 2 (g) ⇌ N 2 H 4 (g)
SO 2 (g) + O 2 (g) ⇌ SO 3 (g)
CS 2 (g) + H 2 (g) ⇌ CH 4 (g) + H 2 S(g)
PCl 5 (g) ⇌ PCl 3 (g) + Cl 2 (g)
3. Balance the following chemical equations and write the equilibrium constant expression.
C(s) + CO 2 (g) ⇌ CO(g)
NH 3 (aq) + H 2 O(l) ⇌ NH 4 + (aq) + OH - (aq)
H 2 SO 4 (aq) + H 2 O(l) ⇌ H 3 O + (aq) + SO 4 2 - (aq)
4. For each reaction, which is greater at equilibrium, the concentration of reactants or products?
Hint: Write an equilibrium constant expression and determine based on the value of the K eq provided.
HPO 4 2 - (aq) + CN - (aq) ⇌ PO 4 3 - (aq) + HCN(aq) K eq = 8.6 X 10 -4
H 3 PO 4 (aq) + CN - (aq) ⇌ H 2 PO 4 - (aq) + HCN(aq) K eq = 1.5 X 10 7
HCO 3 - (aq) + HF(aq) ⇌ F - (aq) + H 2 CO 3 (aq) K eq = 1.5 X 10 3
NH 4 + (aq) + HCO 3 - (aq) ⇌ H 2 CO 3 (aq) + NH 3 (aq) K eq = 1.5 X 10 -3
Strong and Weak Acids
1. Based on the Ka value provided., indicate which acid is stronger of the pair? Which has a lower pH?
a. HClO, K a = 3.0 X 10 -8
b. C 2 O 4 H - , K a = 6.4 X 10 -5
2. Based on the Ka value provided., indicate which acid is stronger of the pair? Which has a lower pH?
a. C 2 O 4 H 2 , K a = 5.9 X 10 -2
b. C 6 O 2 H 8 , K a = 1.7 X 10 -5
3. Based on the Ka value provided., indicate which acid is stronger of the pair? Which has a lower pH?
a. NH 4 + , K a = 5.6 X 10 -10
b. HPO 4 2 - , K a = 4.2 X 10 -13
The pH Scale
Find the pH, given the [H 3 O + ] of the following. Label the solution as acidic, basic, or neutral.
a. 1 ×10 -3 M
b. 2.5 ×10 -11 M
c. 4.7 ×10 -9 M
d. 5.8 ×10 -4 M
e. 1.0×10 -7 M
f. 3.9 ×10 -2
g. 7.0 ×10 -5
h. 6.8 ×10 -7
Le Chatelier's principle
1. For the equilibrium below, what is the effect (give shift) of
S 2 (g) + C(s) ⇌ CS 2 (g)
a. increasing [CS 2 ]
b. decreasing [CS 2 ]
c. decreasing [S 2 ]
2. The enzyme carbonic anhydrase catalyzes the conversion of CO 2 and H 2 O into H 2 CO 3 .
CO 2 (g) + H 2 O(l) ⇌ H 2 CO 3 (aq)
Give shift for b thru f.
a. Write the equilibrium constant expression.
b. What is the effect of doubling the amount of carbonic anhydrase on the equilibrium?
c. What is the effect of increasing [CO 2 ]?
d. What is the effect of decreasing [CO 2 ]?
e. What is the effect of increasing [H 2 CO 3 ]?
f. What is the effect of decreasing [H 2 CO 3 ]?
3. The following reaction happens in step 1 of the citric acid cycle:
Oxaloacetate + Acetyl-CoA + H 2 O ⇌ Citrate + CoA
Give shift for a thru c.
a. What is the effect of decreasing [oxaloacetate]?
b. What is the effect of increasing [oxaloacetate]?
c. What is the effect of increasing [Acetyl-CoA]?
4. The following reaction is from step 5 of glycolysis:
Dihydroxyacetone phosphate ⇌ Glyceraldehyde-3-phosphate
a. What is the effect of removing [Glyceraldehyde-3-phosphate]?
b. What is the effect of adding [Dihydroxyacetone phosphate]?
Buffers
1. What is a buffer solution? What is the composition of a buffer solution? Give an example.
2. Explain with chemical equations, how the H 2 CO 3 /HCO 3 - buffer system helps maintain blood serum at a constant pH.
3. What is the effect of changes in pH on an enzyme structure? Please use the picture of a partial protein strand to show the effect using chemical equations.
4. Severe cases of acidosis may lead to coma and death. Explain with equilibrium equations & Le Chatelier’s principle how the lungs compensate for acidosis.
5. A patient has symptoms of light-headedness associated with acidosis. Explain how the kidney’s compensate for acidosis. Give equilibrium equations and apply Le Chatelier’s principle to explain your answer.
6. Due to excessive use of antacids a patient shows symptoms of alkalosis. Explain how the lungs try to compensate for alkalosis. Give equilibrium equations and apply Le Chatelier’s principle to explain your answer.
7. Symptoms of alkalosis include nervousness and cramps. Explain with chemical equations & equilibrium principles how the kidneys help compensate for alkalosis.