Question

If `pH=8`, what are `[H_3O^+]` and `[HO^-]`?

Answer 1

0.00000001

Explanation:

The conversion from pH to [H+] is: `10^-pH`

Therefore, you can just do the math having that formula and the pH value: `10^-8 = 1 E-8 or 0.00000001`

Keep in mind that some professors/textbooks will use [H3O+] instead of [H+], but they are both referring to the same thing.

Hope this helped (c:

Answer 2

`[H_3O^+]=10^-8*mol*L^-1`

Explanation:

By definition, `pH=-log_10[H_3O^+]`....(note that we use `H^+` and `H_3O^+` interchangeably). And thus if `pH=8`, `[H_3O^+]=10^(-8)*mol*L^-1`.

Note that in aqueous solution,...

`pH+pOH=14`...and so....

....... since `[HO^-]=10^(-6)*mol*L^-1`.....this solution is ALKALINE given that there are more hydroxide ions than hydronium ions....

See here for a fuller description.