Chemistry

Question 1

1Pure water at 25 °C has pH 7.

Easy

A. True B. False

Question 2

2Calculate the pH of a solution with [H⁺] = 10⁻³ mol/dm³.

Medium

A. −3 B. 3 C. 11 D. 4

Question 3

3A basic buffer can be made from

Hard

A. a weak base and its salt with a strong acid B. a strong base alone C. a strong acid and water D. a weak acid alone

Question 4

4Calculate the pH of 1 × 10⁻⁴ mol/dm³ sodium hydroxide solution at 25 °C.

Hard

A. 9 B. 10 C. 11 D. 4

Question 5

5A solution of pH 2 is more acidic than one of pH 5.

Easy

A. True B. False

Question 6

6Calculate the pH of 1 × 10⁻³ mol/dm³ sodium hydroxide solution at 25 °C.

Hard

A. 11 B. 12 C. 3 D. 10

Question 7

7The pH of a solution with [H⁺] = 10⁻⁴ mol/dm³ is ___.

Easy

Your answer (fill in the blank)

Question 8

8The pH of 0.01 mol/dm³ HCl is 1.

Medium

A. True B. False

Question 9

9A weak acid has Ka = 6.4 × 10⁻⁵ mol/dm³. Find the pH of a 0.4 mol/dm³ solution.

Hard

A. 4.19 B. 4.59 C. 0.4 D. 2.3

Question 10

10A weak acid has Ka = 1 × 10⁻⁵ mol/dm³. Find the pH of a 0.4 mol/dm³ solution.

Hard

A. 5 B. 5.4 C. 2.7 D. 0.4