As we know,
pH + pOH = 14
Or,
pOH = 14 - pH
Putting Value of pH,
pOH = 14 - 10.62
pOH = 3.38
pOH is converted into [OH⁻] as follow,
[OH⁻] = 10⁻pOH ∴ -pOH is in power, 10 means antilog
press shift and click log button
[OH⁻] = 10⁻³°³⁸
[OH⁻] = 0.0004168
[OH⁻] = 4.16 × 10⁻⁴
