Seawater has a ph of 8.1. what is the concentration of oh-?

PH scale is used to determine how acidic or basic a solution is.

pH can be calculated as follows;

by knowing the ph we can calculate pOH

pH + pOH = 14

pOH = 14 - 8.1

pOH = 5.9

pOH is used to calculate the hydroxide ion concentration

pOH = - log[OH⁻]

[OH⁻] = antilog (-pOH)

[OH⁻] = 1.26 x 10⁻⁶ M

therefore hydroxide ion concentration is 1.26 x 10⁻⁶ M