Question

A strong monoprotic acid ionizes in water. If the [H3O+] concentration is 1.56 x 10^-4 M, what else is true?

pH = 10.19

The solution contains more hydronium ions than hydroxide ions.

pOH = 1.56 x 10^-4 M

The solution contains equal concentrations of hydroxide and hydronium ions.

Answer 1

Answer: The solution contains more hydronium ions than hydroxide ions.

Step-by-step explanation:

pH or pOH is the measure of acidity or alkalinity of a solution.

pH is calculated by taking negative logarithm of hydronium ion concentration and pOH is calculated by taking negative logarithm of hydroxide ion concentration.

`pH=-\log [H_3O^+]`

`pOH=-log{OH^-}`

`pH+pOH=14`

Given,
`[H_3O^+]=1.56* 10^(-4)M`

`pH=-\log [1.56* 10^(-4)]`

`pH=3.81`

`pH+pOH=14`

`pOH=14-3.81=10.19`

`10.19=-log{OH^-}`

`[{OH^-}]=6.45* 10^(-11)M`

So
`[H^+]` >
`[OH^-]`

Answer 2

I think the correct answer from the choices listed above is the second option. The other true statement would be that the solution contains more hydronium ions than hydroxide ions. Since pH = -log[H3O+]. As pH decreases, the acidity increases. Hope this answers the question.