The concentration of [OH-] -hydroxide ion : 1.2 x 10⁺⁴ M
Further explanation
H₂O ionization reaction
2 H₂O ⇌ OH− + H₃O⁺
The water equilibrium constant (Kw) is the product of concentration
the ions:
Kw = [H₃O +] [OH-]
Kw value at 25° C = 10⁻¹⁴
It is known [H₃O +]=8.4 x 10⁻¹¹ M
then the concentration of [OH-] -hydroxide ion :
[tex]\tt 10^{-14}=8.4\times 10^{-11}\times [OH^-][/tex]
[tex]\tt [OH^-]=\dfrac{10^{-14}}{8.4\times 10^{-11}}=1.19\times 10^{-4}\approx 1.2\times 10^{-4}[/tex]
