Question

Calculate the standard enthalpy of formation of CH3OH(l) from the following data: CH3OH (l) + 3/2 O2(g) → CO2(g) + 2H2O(l) ; ∆rH = –726 kJ mol–1 C(graphite) + O2(g) → CO2(g) ; ∆cH = –393 kJ mol–1 H2(g) + 1/2 O2(g) → H2O(l); ∆f H = –286 kJ mol–1.

(a) Use the information in the table to calculate the enthalpy of this reaction C2H6(g) + 7/2 O2(g) → 2CO2(g) + 3H2O(l) Reactions and ΔHf° kJ/mol: 2C(s) + 3H2(g) → C2H6(g): -84.7 C(s) + O2(g) → CO2(g): -393.5 H2(g) + 1/2 O2(g) → H2O(l): -285.8 (b) Will the heat released in the following two reactions be equal? Give reasons in support of your answer. H2(g) + 1/2 O2(g) → H2O(g) H2(g) + 1/2 O2(g) → H2O(l)