Question

HELP!!!

A solution at 25 degrees Celsius is 1.0 × 10–5 M H3O+. What is the concentration of OH– in this solution?
1.0 × 10–5 M OH–
1.0 × 10–14 M OH–
1.0 × 105 M OH–
1.0 × 10–9 M OH–

Answer 1

1.0 × 10–9 M OH–

Step-by-step explanation:

It is the above answer I just took the test

Answer 2

[OH⁻] = 1.0 x 10⁻⁹ M.

Step-by-step explanation:

∵ [H₃O⁺][OH⁻] = 10⁻¹⁴.

∴ [OH⁻] = 10⁻¹⁴/[H₃O⁺] = 10⁻¹⁴/(1.0 x 10⁻⁵) = 1.0 x 10⁻⁹ M.