Question

What is the ph of a 3.9x10^-8 m oh- solution

Answer 1

The pH of the solution is 6.58.

Step-by-step explanation:

The pOH of the solution is defined as negative logarithm of hydroxide ion concentration.

`pOH=-\log[OH^-]`

The concentration of hydroxide ions =
`[OH^-]=3.8* 10^(-8)M`

`pOH=-\log[3.8* 10^(-8)M]=7.42`

pH + pOH = 14

pH = 14- 7.42 = 6.68

The pH of the solution is 6.58.

Answer 2

6.59.

Step-by-step explanation:

∵ pOH = - log[OH⁻]

∴ pOH = - log[OH⁻] = - log(3.9 x 10⁻⁸) = 7.408.

∵ pH + pOH = 14.0.

∴ pH = 14.0 - pOH = 14.0 - 7.408 = 6.59.