The heats of combustion of carbon hydrogen and acetylene are -394kJ, -286kJ and -1301 kJ respectively. Calculate heat of formation of C_(2)H_(2)

The heats of combustion of carbon hydrogen and acetylene are -394kJ, -

1.	The heats of combustion of carbon hydrogen and acetylene are -394kJ, -286kJ and -1301 kJ respectively. Calculate heat of formation of C_(2)H_(2)
Answer» 621 kJ 454kJ `-227` kJ 227 kJ Solution :Reaction for formation of `C_(2)H_(2)` is `2C_((gr)) + H_(2(g)) rarr C_(2) H_(2(g))` `Delta H` of reaction `= SIGMA` Heat of COMBUSTION of reactants `- Sigma` Heat of formation of products `Delta H= 2 (-394) + (-286) - (-1301) = 227KJ`