if the concentration of hydrogen ions in an aqueous solution at 25 degree celsius is "0.0081" M. What is the concentration of the hydroxide ion?

Answer 1

Hello, Henry,

The equilibrium coefficient of water and its two ions, H⁺ and OH^- is 1.0x10^-14. This means that the product of the H⁺ and OH^- concentrations equals 1.0x10^-14.

In this case, [H⁺] = 8.1x10^-3M

[OH^-] = [1.0x10^-14]/[8.1x10^-3M]

[OH^-] = [1.0x10^-14]/[8.1x10^-3M]

[OH^-] = 1.2346x10^-12

We can calculate pH, which is the negative log of [H⁺]

- log (8.1x10^-3M)

pH = 2.09

pOH would be 14 - 2.09, or 11.81

Bob