Acid Dissociation

A 0.1-Molar solution of acetic acid (CH₃COOH ) has a pH of about

• 1

• 3

• 7

• 10

• 14

The K_a, acid dissociation constant, for an acid is 9 x 10^-4 at room temperature. At this temperature, what is the approximate percent dissociation of the acid in a 1.0 M solution?

• 0.03%

• 0.09%

• 3%

• 5%

• 9%

Phenol, C₆H₅OH, has a K_a =1.0 x 10^-10. What is the pH of a 0.010 M solution of phenol?

• between 3-7

• 10

• 2

• between 7-10

• 7

What is the ionization constant, K_a , for a weak monoprotic acid if a 0.30-molar solution has a pH of 4.0?

• 9.7 X 10^-10

• 4.7 X 10^-2

• 1.7 X 10^-6

• 3.0 X 10^-4

• 3.3 X 10^-8

You are given equimolar solutions of each of the following. Which has the lowest pH?

• NH₄Cl

• NaCl

• K₃PO₄

• Na₂CO₃

• KNO₃

When sodium nitrate is dissolved in water

• the solution is acidic because of the hydrolysis of the sodium ion

• the solution is neutral

• The solution is basic because of hydrolysis of the sodium ion

• The solution is acidic because of hydrolysis of the NO₂^- ion

Determine the OH^-(aq) concentration in 1.0 M aniline (C₆H₅NH₂) solution. ( The K_b for aniline is 4.0 x 10^-10.)

• 2.0 X 10^-5 M

• 4.0 X 10^-10 M

• 3.0 X 10^-6 M

• 5.0 X 10^-7 M

• 1.0 M

H₂C₃H₂O₄ + 2 H₂O « 2 H₃O⁺ + C₃H₂O₄^2-

As shown above, malonic acid is a diprotic acid. The successive equilibrium constants are 1.5 x 10^-3 (K_a1) and 2.0 x 10^-6 (K_a2). What is the equilibrium constant for the above reaction?

• 1.0 X 10^-14

• 2.0 X 10^-6

• 4.0 X 10^-12

• 3.0 X 10^-9

• 1.5 X 10^-3

Which pair of chemical species is not a conjugate acid-base pair?

• H₂CO₃ and CO₃^2-

• OH^- and H₂O

• HPO₄^2- and PO₄^3-

• NH₃ and NH₄⁺

• CH₃NH₂ and CH₃NH^-

All of the following species can function as

Brönsted-Lowery bases in solution EXCEPT

• H₂O

• NH₃

• NH₄⁺

• HCO₃^-