The [OH-] ion concentration of a sample is 1 × 10-10 M. What is the concentration of [H+] in the sample at 25°C?

A. 1 × 10-14 M
B. 1 × 10-4 M
C. 1 × 10-10 M
D. 1 × 10-6 M

To determine the concentration of [H+] in a sample, you can use the concept of Kw, which is the ion product of water. At 25°C, the value of Kw is 1 × 10-14 M2.

The equation for Kw is as follows:
Kw = [H+][OH-]

Given that the [OH-] ion concentration is 1 × 10-10 M, we can rearrange the equation to find [H+]:
[H+] = Kw / [OH-]

Substituting the values, we have:
[H+] = (1 × 10-14 M2) / (1 × 10-10 M)

Simplifying the expression, we get:
[H+] = 1 × 10-14 M / 1 × 10-10 M

Dividing the powers of 10, we can rewrite the expression as:
[H+] = (1 / 1) × (10-14 M / 10-10 M)

Simplifying further, we have:
[H+] = 1 × 10-14-(-10) M

Subtracting exponents with the same base, we get:
[H+] = 1 × 10-4 M

Therefore, the concentration of [H+] in the sample is 1 × 10-4 M.

So, the correct answer is B. 1 × 10-4 M.