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Acids and Bases: Acids Go to the Gym to Get Buffered Quiz

Think you’ve got your head wrapped around Acids and Bases? Put your knowledge to the test. Good luck — the Stickman is counting on you!
Q. What is the equilibrium concentration of F- in a 0.08 M solution of HF (Ka = 3.5 × 10-4)?

0.08 M
2.8 × 10-5 M
5.3 × 103 M
5.3 × 10-3 M
None of the above
Q. If a solution is neutral but the H3O+ concentration is 1 × 10-8 M, what must be the value of Kw?

8
1 × 10 14
1 × 10-12
1 × 10-8
1 × 10-16
Q. How many moles of Mg(OH)2 would be needed to bring 0.85 L of a 0.015 M solution of H2S (Ka 1.0 × 10-7) to the equivalence point?

0.0064
0.13
However many moles it takes to get to pH 7
0.26
0.013
Q. Which buffer solution has the largest buffering capacity: 1 L of 0.5 M HF, 1 L of 0.5 M CH3CH2COOH, or 1.2 M HN3?

The HN3 solution
The HF and CH3CH2COOH solution have equal buffering capacities
The HF solution
The CH3CH2COOH solution
Not enough information is given
Q. Which weak acid and salt combination would be best suited to make a buffer solution at pH 3.3?

HNO2 and NaNO2
HIO4 and KIO4
H3PO4 and NaH2PO4
HCl and ZnCl2
KBr and HBr
Q. Imagine you dissolve a 3.58 g sample of impure phenol (C6H5OH; pKa = 9.89) into water. The resulting solution requires 116.8 mL of 0.18 M NaOH to reach the equivalence point. What is the mass percentage of the phenol in the sample?

3.5
55
45
100
Not enough information provided
Q. Which of the following pairs of molecules could represent a base and conjugate acid pair?

Na+ and Cl-
H2O and OH-
IO3- and HIO3
HF and F-
Al(OH)3 and H2O
Q. What is the pH of 125 mLs of a 0.8 M buffer solution of NH3 (Kb = 1.8 × 10-5) after the addition of 15 mL of 2.6 M HCl?

9.26
9.06
9.89
8.85
9.04
Q. Which of the following bases is most stable relative to its conjugate acid?

IO-
BrO-
ClO-
ClO2-
ClO3-
Q. What is the pH of 0.65 L of a 0.73 M solution of saccharin (C7H5NO3S; Ka = 2.1 × 10-12) at the equivalence point of a titration of this solution with 1.80 M NaOH?

12.7
8.2
10.5
11.8
7.0