Question

As 100 milliliters of 0.10 molar KOH is added to 100 milliliters of 0.10 molar HCl at 298 K, the pH of the resulting solution will

Answer 1

Let us first calculate millimole of H+ and OH- ions.

Millimole of H+ produced by HCl = molarity × volume in ml = 100 × 0.1 = 10

Millimole of OH- produced by KOH = 100 × 0.1 = 10

Since, millimole of H+ = millimole of OH-

=> Solution has equal concentration of H+ and OH- ion.

=> Solution is neutral.

Hence, that pH of the solution is 7.