The work done during the expansion of a gas from a volume of 4 dm³ to 6 dm³ against a constant external pressure of 3 atm is (1 L atm = 101.32 J)

If the bond energies of H $$-$$ H, Br $$-$$ Br, and H $$-$$ Br are 433, 192 and 364 kJ mol^$$-$$1 respectively, the $$\Delta $$H^o for the reaction

H_2(g) + Br_2(g) $$ \to $$ 2HBr_(g) is

The molar heat capacity of water at constant pressure, C, is 75 J K^$$-$$1 mol^$$-$$1. When 1.0 kJ of heat is supplied to 100 g of water which is free to expand, the increase in temperature of water is

For which one of the following equations is $$\Delta $$H^o_react equal to $$\Delta $$H^o_f for the product ?