The mass of water produced upon complete combustion of 15 g of ethane gas is : (Given molar masses in g mol ⁻¹ : C = 12 , H = 1 , O = 16 )

Step-by-step solution

The balanced chemical equation for the complete combustion of ethane is: C ₂ H ₆( g ) + 7 2 O ₂( g ) 2 CO ₂( g ) + 3 H ₂ O ( l ) Molar mass of ethane ( C ₂ H ₆ ) = 2 12 + 6 1 = 30 g mol ⁻¹ Number of moles of ethane = 15 g 30 g mol ⁻¹ = 0.5 mol From the balanced equation, 1 mol of ethane produces 3 mol of water. Therefore, 0.5 mol of ethane will produce 0.5 3 = 1.5 mol of water. Molar mass of water ( H ₂ O ) = 18 g mol ⁻¹ Mass of water produced = 1.5 mol 18 g mol ⁻¹ = 27 g Answer: 27