Question

What is the pH of a 0.059 M aqueous solution of barium hydroxide?

Answer 1

Barium Hydroxide Ba(OH)2 is a strong base and dissociates completely in solution. So, one mole of Ba(OH)2 will give 2 moles of OH- ions according to following equation:

Ba(OH)2 (s) ---> + 2

hence, the solution will have 2*0.059= 0.118M Hydroxide ions.

Now, for water

[H⁺][OH ^-]= 1.0 X 10^-14M

[OH ^-] = 1.18 X 10^-1M

Then, [H⁺]= 1.0 X 10^-14M / 1.18 X 10^-1M

=> 8.5 X 10^-14 M

Therefore, pH = - log ₁₀([H⁺] = 8.5 X 10^-14) = -log8.5 + 14

=> 14 - 0.93 = 13.07 is the pH of the given solution.