Consider the reaction : $N_2 + 3H_2 \to 2NH_3$ carried out at constant temperature and pressure. If $\Delta H$ and $\Delta U$ are the enthalpy and internal energy changes for the reaction, which of the following expressions is true ?

Question

( A ) $\Delta H = 0 $
( B ) $\Delta H = \Delta U$
( C ) $\Delta H < \Delta U$
( D ) $\Delta H > \Delta U$