Question

What is the ph of a neutral solution at 25°c?

Answer 1

pH = 7.00

Step-by-step explanation:

In water at 25 °C,

`K_(w) = [\text{H}_(3)\text{O}^(+)][\text{OH}^(-)] = 1.01 * 10^(-14)\\`

The solution is neutral, so
`[\text{H}_(3)\text{O}^(+)] = [\text{OH}^(-)]\\`

`[\text{H}_(3)\text{O}^(+)]^(2) = 1.01 * 10^(-14)\\`

`[\text{H}_(3)\text{O}^(+)] = \sqrt{1.01 * 10^(-14)} = 1.00 * 10^(-7)`

To get the pH, you take the negative logarithm of the hydronium ion concentration.

`\text{pH} = -\log{( 1.00 * 10^(-7))} = 7.00\\`