Question

Consider the reaction, `N_(2)(g)+3H_(2)(g)rarr2NH_(3)(g)`, carried out at constant temperature and pressure. If `Delta H` and `Delta U` are enthalpy change and internal energy change respectively, which of the following expressions is true ?
A. `Delta H=0`
B. `Delta H=Delta U`
C. `Delta H lt Delta U`
D. `Delta H gt Delta U`

Answer 1

Correct Answer - C
`N_(2)+3H_(2)rarr2NH_(3)" " Deltan=2-4= -2`
`Delta H=DeltaU+Delta nRT=Delta U-2RT" " :. Delta H lt Delta U`