Question

25.0cm^3 of 0.100mol/dm^3 aqueous sodium hydroxide is neutralised by 24.6cm^3 of dilute sulfuric acid. What is the concentration of the dilute sulfuric acid?

Answer 1

Explanation:

1 dm3 = 1000 cm3.

25.0 cm3 0.100 mol/dm3 NaOH solution contains (25/1000)×0.100 = 0.0025 mol NaOH.

2NaOH + H2SO4 → Na2SO4 + H2O

2 moles of NaOH neutralizes 1 mole of H2SO4.

Therefore, 0.0025 moles of NaOH neutralizes 0.0025/2 = 0.00125 moles of H2SO4.

So, the molarity of H2SO4 solution = (0.00125/24.6) × 1000 = 0.0508 mol/dm3.