Question

Calculate [H3O+] and [OH−] for each of the following solutions at 25 ∘C given the pH.
pH= 2.89

Answer 1

Answer: The value of
`[H_(3)O^(+)]` is 0.0012 M and
`[OH^(-)]` is
`1.02 * 10^(-14)`.

Step-by-step explanation:

pH is the negative logarithm of concentration of hydrogen ion.

It is given that pH is 2.89. So, the value of concentration of hydrogen ions is calculated as follows.

`pH = - log [H^(+)]\\2.89 = - log [H^(+)]\\conc. H^(+) = 0.0012 M`

The relation between pH and pOH value is as follows.

pH + pOH = 14

0.0012 + pOH = 14

pOH = 14 - 0.0012 = 13.99

Now, pOH is the negative logarithm of concentration of hydroxide ions.

Hence,
`[OH^(-)]` is calculated as follows.

`pOH = - log [OH^(-)]\\13.99 = - log [OH^(-)]\\conc. OH^(-) = 1.02 * 10^(-14) M`

Thus, we can conclude that the value of
`[H_(3)O^(+)]` is 0.0012 M and
`[OH^(-)]` is
`1.02 * 10^(-14)`.