Question

3) In peaches, [OH]=3.16x10-11 M

a) Find [H+ ]

b) What is the pH?

c) Is the solution acidic, basic, or neutral?

Answer 1

Answer:

a) [H⁺] = 3.16 x 10⁻⁴ M.

b) pH = 3.5.

c) The solution is acidic.

Explanation:

a) Find [H⁺]

∵ [H⁺] [OH⁻] = 10⁻¹⁴.

∴ [H⁺] = 10⁻¹⁴/ [OH⁻] = 10⁻¹⁴/ (3.16 x 10⁻¹¹ M) = 3.16 x 10⁻⁴ M.

b) What is the pH?

∵ pH = - log[H⁺].

[H⁺] = 3.16 x 10⁻⁴ M.

∴ pH = - log(3.16 x 10⁻⁴ M) = 3.5.

c) Is the solution acidic, basic, or neutral?

• We can determine the nature of the solution, acidic, basic or neutral, from the value of the pH.

pH is a scale from 0 to 14.

• If pH < 7, the solution is acidic.

• If pH = 7, the solution is neutral.

• If pH > 7, the solution basic.

∵ pH = 3.5 < 7.

∴ The solution is acidic.