The standard enthalpies of formation of H_(2)O_(2(l)) and H_(2)O_((l)) " are " -187.8 kJ "mole"^(-1) and -285.8 kJ "mole"^(-1) respectively. The Delta H^(0) for the decomposition of one mole of H_(2)O_(2(l)) " to " H_(2)O_((l)) and O_(2(g)) is

The standard enthalpies of formation of H_(2)O_(2(l)) and H_(2)O_((l))

1.	The standard enthalpies of formation of H_(2)O_(2(l)) and H_(2)O_((l)) " are " -187.8 kJ "mole"^(-1) and -285.8 kJ "mole"^(-1) respectively. The Delta H^(0) for the decomposition of one mole of H_(2)O_(2(l)) " to " H_(2)O_((l)) and O_(2(g)) is
Answer» `-473.6 kJ. "mole"^(-1)` `-98.9 kJ "mole"^(-1)` `+473.6 kJ "mole"^(-1)` `+187.8 kJ "mole"^(-1)` Solution :The GIVEN reaction is `H_(2)O_(2(l)) rarr H_(2)O_((l)) + (1)/(2) O_(2(g))` `Delta H= Sigma` Heat of formation of PRODUCTS `-Sigma`Heat of formation of reactants `=(-285.8) + (0) - (-187.8) = -98`