Chem 1412

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

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

All of the following species can function as

Brönsted-Lowery bases in solution EXCEPT

• H₂O

• NH₃

• NH₄⁺

• HCO₃^-

How many moles of HCOONa must be added to 1.0 L of 0.10 M HCOOH to prepare a buffer solution with a pH of 3.4? (HCOOH K_a = 2 x 10¯⁴)

• 0.01

• 0.05

• 0.1

• 0.2

A buffer solution is prepared by mixing equal volumes of 0.50 M weak acid with 1.0 M of its conjugate base. Based on the data given in the table above, which of the following pairs of chemical solutions should be used to prepare the buffer solution so that the pH will be between 4 and 7?

• CH₃COOH and NH₃

• CH₃COOH and CH₃COONa

• H₂CO₃ and NH₃

• H₂CO₃ and Na₂CO₃

Which of the following best approximates the K_a value for this weak acid?

• 1 x 10^–3

• 1 x 10^–4

• 1 x 10^–5

• 1 x 10^–6

Which of the following is a conjugate acid/base pair?

• HCl/OCl^-
• H₂SO₄/SO₄^2-
• NH₄⁺/NH₃
• H₃O⁺/OH^-