Answer :
Answer
[OH⁻] = 2.6 x 10⁻¹¹ M
Explanation
Given that:
[H₃O⁺] = 3.9 x 10⁻⁴ M
What to find:
[OH⁻]
Step-by-step solution:
For any aqueous solution, the product of [H₃O⁺] and [OH⁻] is given by:
[H₃O⁺] x [OH⁻] = 1.0 x 10⁻¹⁴
If one increases, the other decreases.
Putting [H₃O⁺] = 3.9 x 10⁻⁴ M into the formula above, we have:
[tex]\begin{gathered} 3.9\times10⁴\times\left[OH⁻\right]=1.0\times10⁻¹⁴ \\ \\ \left[OH⁻\right]=\frac{1.0\times10⁻¹⁴}{3.9\times10⁻⁴} \\ \\ \left[OH⁻\right]=2.6\times10^{-11}\text{ }M \end{gathered}[/tex]Hence, [OH⁻] = 2.6 x 10⁻¹¹ M