Acid base theory

Question

at 15c the value of kw is 4.5x10^-15. what is the equilibrium concentration of oh^- at this temperature

Answer 1

Acid base theory

at 15c the value of kw is 4.5x10^-15. what is the equilibrium concentration of oh^- at this temperature

Hello Mo,

Assuming the solution is neutral at pH = 7. Then, Ka = Kb

recall that Kw = Ka * Kb

So,

Kw = Ka * Kb

4.5 x10^-15 = Ka * Kb

4.5 x10^-15 = x * x

4.5 x10^-15 = x²

x = √(4.5 x 10^-15 )

x = 6.7 x 10^-8

Use the fact that [OH-] = Kb

[OH-] = 6.7 x 10^-8