During a laboratory experiment, 3.0 g of pure methane gas is burnt completely in excess oxygen. Calculate the volume of carbon dioxide produced at NTP (assume 1 mol gas = 22.4 L).

easy 3 marks Class 10 · Science · Carbon and its Compounds

Answer

4.2 L

The correct answer is 4.2 L — Therefore the volume of $ce C O 2$ is $4.2 L$ .

Step-by-step solution

Determine the molar mass of methane: $M_{ce C H 4} = 16.0 g, mo l^{- 1}$ .
Convert the mass of methane to moles: $n_{ce C H 4} = \frac{3.0 g}{16.0 g , mo l ^{- 1}} = 0.1875 mol$ .
From the balanced equation $ce C H 4 + 2 O 2 - > C O 2 + 2 H 2 O$ , 1 mol $ce C H 4$ produces 1 mol $ce C O 2$ . So $n_{ce C O 2} = 0.1875 mol$ .
Use the molar volume at NTP: $V = n \times 22.4 L, mo l^{- 1} = 0.1875 \times 22.4 = 4.2 L$ .
Therefore the volume of $ce C O 2$ is $4.2 L$ .

Common mistake: Using the molar volume of 22.4 L at STP instead of NTP or miscalculating moles of methane

Concept tested: Combustion of methane