(c) Work done in a chemical reaction, W = -ΔngRT Where, Δng = number of moles of gaseous products - number of moles of gaseous reactants. Reaction involved in combustion of ethane is, C2H6(g)+
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2
O2(g) → 2CO2(g)+3H2O(l) ∴ Δng=2−4.5=−2.5 W=(2.5mol)(8.314JK−1mol−1) × 300 K =6235.5J=6.2355KJ 1 mole of C2H6=30g of C2H6 Work done during combustion of 30 g ofC2H6 = 6.2355 kJ ∴ Work done during combustion of 90g of C2H6 =