pH Assignment and Quiz

What is the equilibrium constant of pure water at 25°C?

10-14

Which statement about the self-ionization of water is correct?

Two water molecules interact to form a hydronium ion and a hydroxide ion.

A solution containing HCl would likely have

a low pH and a high pOH

Select the most acidic solution from these options. Select the most basic (alkaline) solution from these options. Select the least acidic solution from these options.

solution B, pH = 1 solution C, pH = 13 solution A, pOH = 1

Rank these solutions from the most alkaline (1) to the least alkaline (5). pOH = 0.5 pH = 3.5 [OH-] = 5.62 × 10-5 M [H3O+] = 3.16 × 10-7 M pH = 0.5

1 4 2 3 5

Which would most likely be the pH of a highly-corrosive acid?

1

What is the pH of a solution with [H+] = 1.25 x 10-10 M?

9.90

What is the pH of a KOH solution that has [H+] = 1.87 × 10-13 M? What is the pOH of a KOH solution that has [OH− ] = 5.81 × 10−3 M? What is the pH of a solution of NaCl that has [H+] = 1.00 × 10-7 M?

12.7 2.24 7.00

Rank the following solutions from the highest [H3O+] (1) to the lowest [H3O+] (5).

2 5 1 3 4

What is the hydronium ion concentration in a solution of HCl that has a pH of 4.65? What is the hydroxide ion concentration in a solution of NH3 with a pOH of 4.65?

2.24 × 10-5 M 2.24 × 10-5 M

A chemist makes a solution of NaOH for use in an experiment. She dissolves 0.00500 mol NaOH in 1.00 L H2O. The NaOH completely dissociates to form a solution with [OH− ] = 0.00500 M. What is the pOH of this solution?

2.30

rainwater, pOH = 8.5 cola, pOH = 11 tomato juice, pOH = 10 liquid drain cleaner, pOH = 0

acidic acidic acidic basic

Which describes an alkaline solution?

basic

Which of these solutions has the highest concentration of H+?

solution C, pH = 2.5

A chemist makes a solution of NaOH for use in an experiment. She dissolves 0.00500 mol NaOH in 1.00 L H2O. The NaOH completely dissociates to form a solution with [OH− ] = 0.00500 M. What is the pH of the solution?

11.7

A substance with a high pOH would likely have which of the following?

A high [H+ ] and a low pH

Which statement best describes the pH of pure water?

It is neutral because the concentration of hydronium ions equals that of hydroxide ions.

Which of these statements best explains why pure water has a pH of 7?

Water self-ionizes to form an equilibrium system that has [H3O+] = 1.0 × 10-7 M.

pure water, pH = 7.0 lake water, pH = 6.5 baking soda solution, pH = 9 soapy water, pH = 12

neutral acidic basic basic

Based on the definition of logarithms, what is the difference in hydrogen ion concentration between a substance with a pH of 2 and a substance with a pH of 3?

A substance with a pH of 2 has a 10 times higher concentration of H+ than a substance with a pH of 3.

A substance with a high [H+ ] would likely have which additional characteristics?

a low [OH- ] and a high pOH