Question

∆U⊖ of combustion of methane is – X kJ mol–1. The value of ∆H⊖ is

The reaction of cyanamide, NH2CN (s), with dioxygen was carried out in a bomb calorimeter, and ∆U was found to be –742.7 kJ mol–1 at 298 K. Calculate enthalpy change for the reaction at 298 K. NH2CN(g) + 3/2 O2(g) → N2(g) + CO2(g) + H2O(l)

For the reaction, 2 Cl(g) → Cl2(g), what are the signs of ∆H and ∆S ?

Comment on the thermodynamic stability of NO(g), given 1/2 N2(g) + 1/2 O2(g) → NO(g); ∆rH⊖ = 90 kJ mol–1 NO(g) + 1/2 O2(g) → NO2(g): ∆rH⊖ = –74 kJ mol–1