Question

From the equation:

\[\ce{C + 2H2SO4 -> CO2 + 2H2O + 2SO2}\]

Calculate:

1. the mass of carbon oxidized by 49 g of sulphuric acid (C = 12, relative molecular mass of sulphuric acid = 98)
2. the volume of sulphur dioxide measured at STP, liberated at the same time.
   (Volume occupied by 1 mole of a gas at STP is 22.4 dm³).

From the equation:

\[\ce{C + 2H2SO4 -> CO2 + 2H2O + 2SO2}\]

Calculate:

1. the mass of carbon oxidized by 49 g of sulphuric acid.
2. the volume of sulphur dioxide measured at STP, liberated at the same time.
   (Volume occupied by 1 mole of a gas at STP is 22.4 dm³).

Answer 1

\[\ce{\underset{12 g}{C2} + \underset{2(98)}{2H2SO4} -> CO2 + 2H2O + 2SO2}\]

i. 196 g of sulphuric acid is required to oxidise 12 g of carbon.

1 g of sulphuric acid is required to oxidise `12/196` g of carbon.

49 g of sulphuric acid is required to oxidise `12/196 xx 49` g of carbon = 3 g of carbon.

ii. 12 g of carbon will liberate (22.4 × 2) litres of SO₂.

1 g of carbon will liberate `(22.4 xx 2)/12` litres of SO₂.

3 g of carbon will liberate `(22.4 xx 2)/12 xx 3` litres of SO₂ = 11.2 litres of SO₂.