Question

100. mLmL of 0.200 MMHClHCl is titrated with 0.250 MMNaOHNaOH. Part A What is the pH of the solution at the equivalence point? Express the pH numerically.

Answer 1

Answer:

pH = 7.0

Explanation:

When HCl reacts with NaOH, H₂O and NaCl are produced, thus:

HCl + NaOH → H₂O + NaCl

At equivalence point, all HCl reacts with NaOH. The only you will have is water.

Equilbrium of water is:

H₂O(l) ⇄ H⁺(aq) + OH⁻(aq)

K = 1x10⁻¹⁴ = [H⁺] [OH⁻]

As H⁺ = OH⁻ because both are produced from the same water-

1x10⁻¹⁴ = [H⁺]²

1x10⁻⁷M = [H⁺]

As pH = -log= [H⁺]

pH = 7.0

-The pH at equivalence point in the titration of a strong acid with a strong base is always 7.0-