Question

Solution has [H3O+] = 7.4×10−5 M . Use the ion product constant of water

Answer 1

The concentration of hydroxide ions in the solution is approximately 1.35 x
`10^-10 M`.

To find the [OH-] of the solution, we can use the ion product constant of water (Kw), which is equal to the product of the concentrations of hydrogen ions ([H3O+]) and hydroxide ions ([OH-]).

The ion product constant of water, Kw, is a constant value at a given temperature. At 25°C, Kw is equal to 1.0 x
`10^-14`.

In this question, we are given the concentration of hydrogen ions, [H3O+], which is 7.4 x
`10^-5`MM. To find the concentration of hydroxide ions, [OH-], we can rearrange the equation for Kw:

Kw = [H3O+][OH-]

Substituting the given concentration of hydrogen ions, we have:

1.0 x
`10^-14` = (7.4 x
`10^-5`)([OH-])

To solve for [OH-], divide both sides of the equation by (7.4 x
`10^-5`):

[OH-] = (1.0 x
`10^-14`) / (7.4 x
`10^-5`)

Calculating this expression, we find:

[OH-] ≈ 1.35 x
`10^-10` M

Therefore, the concentration of hydroxide ions in the solution is approximately 1.35 x
`10^-10` M.