Question

What is the hydronium ion concentration of 0.0038 M Ba(OH)₂ solution?

Answer 1

Ba(OH)₂ strong electrolyte it can completely dissociated into constituted ions.

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

0.0038 M                                        0.0038M      2 x 0.0038M

[OH-] = 2 x 0.0038M =7.6 x 10^-3 M

we know relation between H3O+ and OH- ion concentration

Kw = [H3O+][OH-]

[H3O+] = Kw/[OH-]

         = 1.0 x 10^-14 /7.6 x 10^-3

        = 1.31 x 10^-12 M

hydronium ion concentration [H3O+] =1.31 x 10^-12 M