If the pH is 4.5, what is the pOH?

PH+pOH=14

4.5+pOH=14

pOH=14-4.5

pOH = 9.5

We know that

[H⁺][OH⁻]=10⁻¹⁴, so

-log ( [H⁺][OH⁻]) = - log10⁻¹⁴

-log [H⁺] + ( - log[OH⁻]) = - log10⁻¹⁴,

- log [H⁺] = pH

- log[OH⁻] = pOH

- log10⁻¹⁴ = - (-14) log10=14*1=14

pH + pOH = 14