The enthalpies of combustion of C2H6(g), graphite and H2(g) are -1560, -393.5 and -285.8 kJ mol^-1 respectively (H2O formed as liquid). The standard enthalpy of formation of ethane is

JEE Main levelSingle correct optionDifficulty 2 of 3td083

The enthalpies of combustion of $C X_{2} H X_{6} (g)$ , graphite and $H X_{2} (g)$ are $- 1560$ , $- 393.5$ and $- 285.8 kJ mo l^{- 1}$ respectively ( $H X_{2} O$ formed as liquid). The standard enthalpy of formation of ethane is

For

2 C + 3 H X_{2} C X_{2} H X_{6}

Δ_{f} H = \sum Δ_{c} H (reactants) - \sum Δ_{c} H (products) = 2 (- 393.5) + 3 (- 285.8) - (- 1560) = - 84.4 kJ mo l^{- 1}