Saved Bookmarks
| 1. |
Calculate the heat of combustion of ethane, in the reaction C2H6(g) + 3 1/2O2(g) → 2CO2(g) + 3H2O(l) where the heats of formation of ethane gas, carbon dioxide gas and water liquid are –84.7 kJ mol^-1, -393.5 kJ mol^-1 and –285.8 kJ mol^-1 respectively.(a) -1559.7 kJ mol^-1(b) -155.7 kJ mol^-1(c) -159.7 kJ mol^-1(d) -559.7 kJ mol^-1This question was addressed to me by my college director while I was bunking the class.Asked question is from Thermodynamics topic in chapter Thermodynamics of Chemistry – Class 11 |
|
Answer» CORRECT answer is (a) -1559.7 kJ mol^-1 To explain: GIVEN that C2H6(g) + 3 1/2 O2(g) → 2CO2(g) + 3H2O(l) As we know that, ΔHr = Σ ΔHf[products] – Σ ΔHf[REACTANTS]; ΔHc(C2H6) = 2 X (-393.5 kJ mol^-1) + 3 X (-285.8 kJ mol^-1) – (- 84.7 kJ mol^-1) – 2 X (0 kJ mol^-1) = ΔHc(C2H6) = – 1559.7 kJ mol^-1. |
|