Question

A student prepares a solution of sodium sulfate, Na,SO,, by adding 6.25 x 10-2 mol dm-8

sulfuric acid, H, SO;, from a burette to 25.0 cm° of 0.124 mol dm-3 NaOH in a conical flask.

2NaOH(ag) + HaS0, (aq) -› NaySO,(aq) + 2H, 0()

Calculate the minimum volume of the H,SO, that the student would need to completely react

with the NaOH present.

Answer 1

2NaOH + H₂SO₄ --> Na₂SO₄ + 2H₂O

According to the equation,

$n(NaOH)=2{n(H_2SO_4)}$

Therefore,

$C_{NaOH}V_{NaOH}=2C_{H_2SO_4}V_{H_2SO_4};$

$V_{H_2SO_4}=\frac{C_{NaOH}V_{NaOH}}{2C_{H_2SO_4}}=\frac{25.0\ cm^3\times0.124\ M}{2\times0.0625\ M}=24.8\ cm^3$

Answer: 24.8 cm³