Question

1) When a 21.5 mL sample of a 0.337 M aqueous nitrous acid solution is titrated with a 0.373 M aqueous sodium hydroxide solution, what is the pH after 29.1 mL of sodium hydroxide have been added

2) A 28.6 mL sample of 0.226 M methylamine, CH₃NH₂, is titrated with 0.221 M nitric acid.
After adding 11.5 mL of nitric acid, the pH is

3) A 24.0 mL sample of 0.372 M methylamine, CH₃NH₂, is titrated with 0.381 M hydrochloric acid.
After adding 35.9 mL of hydrochloric acid, the pH is

Answer 1

1)

21.5 mL sample of a 0.337 M aqueous nitrous acid solution contains

nitrous acid.

29.1 mL of 0.373 M aqueous sodium hydroxide solution contains

of sodium hydroxide

7.25 mmol of nitrous acid are completely neutralised with 7.25 mmol of sodium hydroxide

of sodium hydroxide remains unneutralised.

Total volume is