Answer :
[OH⁻]= 2.7 x 10⁻¹³
pH = 1.431
Further explanation
Given
[H3O+] = 3.7x10⁻² M.
Required
the [OH-] and pH
Solution
pH = - log [H⁺]
pH = 2 - log 3.7
pH = 1.431
pOH = 14 - 1.431
pOH = 12.569
pOH = - log [OH⁻]
[OH⁻]= 2.7 x 10⁻¹³
or
[OH-][H3O+]=10⁻¹⁴
[OH-]=10⁻¹⁴ : 3.7 x 10⁻²
[OH-] = 2.7 x 10⁻¹³