Question

If [OH–] = 0.250 × 10¹ M, then what is [H+]?

A. 4.0 × 10‒14 M
B. 2.5 × 10‒14 M
C. 1.0 × 10‒13 M
D. 2.0 × 10‒13 M

Answer 1

The concentration of hydrogen ions [H+] given the hydroxide ion concentration [OH-] of 2.5 × 10-1 M can be calculated using the water ion product constant, Kw = 1.0 × 10-14. The hydrogen ion concentration turns out to be 4.0 × 10-14 M, which is option (A).

Step-by-step explanation:

To find the concentration of hydrogen ions [H+] given the hydroxide ion concentration [OH−], we can use the ion product constant for water, Kw, which at 25°C is always equal to 1.0 × 10−14. The equation is Kw = [H+][OH−]. Given that [OH−] is 0.250 × 101 M or 2.5 × 10−1 M, we can rearrange the equation to solve for [H+]:

[H+] = Kw / [OH−] = 1.0 × 10−14 / 2.5 × 10−1 M = 4.0 × 10−14 M

Therefore, the concentration of hydrogen ions is 4.0 × 10−14 M, which corresponds to option (A).