Question

A solution of an acid in water has a hydronium ion concentration of 2.0 × 10-6 M. What is the concentration of hydroxide ion at 25 °C?

If you need to write scientific notation answer type it using "e" instead of 10 as in example below:
11.234×10⁴=11.234e⁻⁴
2.34×10³=2.34e³

Answer 1

The concentration of hydroxide ion (OH-) in a solution with a hydronium ion concentration of 2.0 × 10^-6 M at 25 °C is 5.0 × 10^-9 M, which is calculated using the ion product constant for water (Kw) at 25 °C.

Step-by-step explanation:

To calculate the concentration of hydroxide ion (OH-) at 25 oC for a solution with a hydronium ion (H3O+) concentration of 2.0 × 10-6 M, we use the ion product constant for water (Kw) at 25 oC, which is 1.0 × 10-14.

The formula to find the OH- concentration is: Kw = [H3O+] × [OH-]

We rearrange the formula to solve for [OH-]:
[OH-] = Kw / [H3O+]

Plugging in the values:
[OH-] = (1.0 × 10-14) / (2.0 × 10-6 M)

Therefore, the hydroxide ion concentration is 5.0 × 10-9 M.