Question

What is the pH of a solution that has a hydronium ion concentration of `1.00*10^-10` M?

Answer 1

Take the negative log of your `H_3O^+` molarity.

Explanation:

The pH of an aqueous solution can be found simply by taking the negative logarithm of your hydronium ion concentration, or stated mathematically,

pH = `-log[H_3O^+]`

So, if we plug in your numbers we'll get:

pH = `-log[1.00*10^-10]`

Throw that bad boy in your calculator and you'll find your pH. Or I can just tell you. (It's 10.)