If the pH of a solution is 11.2, then the concentration of [OH-] is 1.585×10³M.
The pH of a solution is a measure of the concentration of hydrogen ions (H+), which in turn is a measure of acidity.
Given : pH of a solution=11.2
we know that pH + pOH = 14
pOH = -log[OH-]
pOH = 14 - pH
= 14 - 11.2
pOH = 2.80
-log[OH-] = 2.80
log[OH-] = -2.80
[OH-] = 10∧-2.80
[OH-] = 1.585 ×10∧-3 M.