Question

Question #231e7

Answer 1

`["H"_3"O"^+] = 1.1xx10^-13` `M`

Explanation:

We're asked to find the hydronium ion concentration `["H"_3"O"^+]`, given the hydroxide ion concentration `["OH"^(-)]`.

At `25` `""^"o""C"`, we have the relationship

`ul(K_w = ["OH"^(-)]["H"_3"O"^+] = 1.00xx10^-14color(white)(l)M^2`

Since `["OH"^- ]` is given as

`9.0xx10^-2` `M`

we plug that into the equation and solve for `["H"_3"O"^+]`:

`["H"_3"O"^+] = (1.00xx10^-14color(white)(l)M^2)/(9.0xx10^-2color(white)(l)M) = color(red)(ulbar(|stackrel(" ")(" "1.1xx10^-13color(white)(l)M" ")|)`

rounded to `2` significant figures.