Question

If the [H+] changed from [1 x 10-7] to [1 x 10-4], what is the new [OH-]?

Answer 1

The new [-OH] is [1x10*-10]

Answer 2

The new concentration of hydroxide ions is
`1* 10^(-10) M`.

Step-by-step explanation:

Concentration of
`H^+` ions =
`[H^+]=1* 10^(-7) M`

When concentration of
`H^+` ions changed to
`1* 10^(-4) M`

`[H^+]'=1* 10^(-4) M`

The pH of the solution will changes to:

`pH=-\log[H^+]'=-\log[1* 10^(-4)]=4`

pH+pOH = 14

pOH = 14 - 4 = 10

And we know that :

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

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

`[OH^-]=1* 10^(-10) M`

The new concentration of hydroxide ions is
`1* 10^(-10) M`.