Question

What is pH of an aqueous solution of 7.25×10^-2 barium hydroxide? show work

Answer 1

Given

Concentration of Ba(OH)₂ = 7.25 * 10^-2 moles/L

Ba(OH)₂ is a strong base hence in aqeuous solution it will completely diassociate into

Ba(OH)₂ ----> Ba²⁺ + 2 OH^-

so each moles of Ba(OH)₂ will give 2 moles of  OH^-

so concentration of  OH^- = 2 * Concentration of Ba(OH)₂ = 2 * 7.25 * 10^-2 moles/L = 14.5 * 10^-2 moles/L

[OH-] = 14.5 * 10^-2 moles/L

pOH = -log([OH^- ]) = -log(14.5 * 10^-2) = 0.8386

pH = 14 - pOH = 14 - 0.8386 = 13.16

Answer pH = 13.16