Question

If pH of a solution is 3.12, what would be the concentration of H⁺ ion?

Options

• 7.586 x 10^-3M

• 7.586 x 10^-4M

• 7.586 x 10^-2M

• 7.586 x 10^-5M

Answer 1

7.586 x 10^-4M

Explanation:

`pH=-log_10[H_3O^⊕]`

`log_10[H_3O^⊕]=-pH`

`=-3.12`

`=-3-0.12+1-1`

`=(-3-1)+1-0.12`

`=-4+0.88=bar(4).88`

Thus `[H_3O^⊕]="antilog"[bar(4).88]`

`=7.586xx10^-4M`