CHEM FINAL (test3)

12) At which point on the titration curve is [A-] closest to being equal to that of [HA]? a. R b. S c. T d. U

A

5) Which of the four acids listed in the table is hydrobromic acid? a. Acid 1 b. Acid 2 c. Acid 3 d. Acid 4

A

8) A 25 mL sample of a 1.0 M solution of acid 1 is mixed with 25 mL of 0.50 M NaOH. What do you expect the pH to be of the resulting solution? a. pH < 7 b. pH = 7 c. pH > 7 d. pH cannot be determined

A

9) Which of the following statements best explains the experimental findings about the strength of the acid, HA? a. HA is a strong acid, as evidenced by the larger volume of HA needed to reach the equivalence point. b. HA is a weak acid, as is evidenced by the pH > 7 at the equivalence point c. HA is a strong acid, as is evidenced by the pH > 7 at the equivalence point d. HA is a weak acid, as evidenced by the larger volume of HA needed to reach the equivalence point

A

10) The concentration of HA is closest to which of the following? a. 0.25 M b. 0.80 M c. 1.00 M d. 1.25 M

B

11) At point Q in the titration, which of the following species has the highest concentration? a. HA b. A- c. H3O+ d. OH-

B

2) A solution is prepared by adding 100. mL of 1.0 M NH3(aq) to 100. mL of 1.0 M NH4Cl(aq). The solution is stirred and its pH is measured to be 9.26. After 3 drops of 1.0 M HCl are added to the solution, the pH of the solution is measured and is still 9.26. Which of the following equations represents the chemical reaction that accounts for the fact that acid was added but there was no detectable change in pH? a. H+(aq) + Cl-(aq) HCl(g) + H2O(l) b. H+(aq) + NH3(aq) NH4+(aq) c. H+(aq) + OH-(aq) H2O(l) d. H+(aq) + NH4+(aq) NH5+2(aq)

B

The pH of solutions of four acids prepared at various concentrations were measured and recorded in the table above. The four acids are, in no particular order, hydrofluoric acid (HF), hydrobromic acid (HBr), bromous acid (HBrO2), hypobromous acid (HBrO), and 4) For which acid is the value of the acid dissociation constant, Ka, the smallest? a. Acid 1 b. Acid 2 c. Acid 3 d. Acid 4

B

1) Based on the information above, which of the following species will be present in a 1.0M H2CO3 solution at the lowest concentration? a. H+ b. HCO3- c. CO3-2 d. H2CO3

C

6) Of the following species, which has the greatest concentration in a 1.0 M solution of Acid 2 at equilibrium? a. OH- b. H3O+ c. Acid 2 d. The conjugate base of acid 2

C

3) When 300. mL of 1.0 M NaOH(aq) is added to 200. mL of 1.0 M HCl(aq), the pH of the resulting mixture is closest to a. 1.0 b. 3.0 c. 7.0 d. 13.0

D

7) If equal volumes of the four acids at a concentration of 1.00 M are each titrated with a strong base, which will require the greatest volume of base to reach the equivalence point? a. Acid 1 b. Acid 2 c. Acid 3 d. Acid 4

D