Question

If 20 ml 0.15 M HCl solution is added to a 10 ml 0.1 M 10 Ba(OH)₂ solution, what will be the pH of the resulting mixture?

Answer 1

20 ml 0.15 M HCl solution is added to a 10 ml 0.1 M 10 Ba(OH)₂ solution

Mole = concentration * volume

Mole of Ba(OH)₂ =0.1 * 10 = 1

Mole of HCl = 20 * 0.15 = 3

10 moles of Hcl is neutralized by 10 moles of Ba(OH)₂hence 20-10 = 10 moles of Hcl

Con of H+ = number of mole of H+ / total volume of solution = 10 / 30ml

Then put it in the formula,

pH = loh (H+) = log (1/3)