Question

If 20 ml 0.5 M NaOh solution is added to a 10 ml 0.1 M 10 H₂SO₄ solution, what will be the pH of the resulting mixture?

Answer 1

20 ml 0.5 M NaOh solution is added to a 10 ml 0.1 M 10 H₂SO₄ solution

Mole = concentration * volume

Mole of H₂SO₄ =0.1 * 10 = 1

Mole of NaOH = 20 * 0.5 = 10

10 moles of NaOh is neutralized by 10 moles of H₂SO₄ hence 20-10 = 10 moles of NaOH

Con of OH- = number of mole of OH- / total volume of solution = 10 / 30ml

Then put it in the formula,

pH = loh (OH-) = log (1/3)