question_answer

Consider the reaction \[{{N}_{2}}+3{{H}_{2}}\xrightarrow{\,}2\,N{{H}_{3}}\] 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?     AIEEE  Solved  Paper-2005

A) \[\Delta H>\Delta U\]                   

B) \[\Delta H<\Delta U\]   

C)        \[\Delta H=\Delta U\]   

D)        \[\Delta H=0\]

Correct Answer: B

Solution :

enthalpy change (at constant pressure) internal energy change (at constant volume) (given reaction is exothermic) mole of (gaseous products gaseous reactants) Thus,            Note Numerical valuein exothermic reaction and when.