Question

A mixture of $2$ moles of carbon monoxide and one mole of oxygen in a closed vessel is ignited to get carbon di oxide. If $\Delta H$ is the enthalpy change and $\Delta E$ is the change in internal energy, then:

• A. $\Delta H>\Delta E$
• B. $\Delta H<\Delta E$
• C. $\Delta H=\Delta E$
• D. not definite

Answer 1

The correct option is B $\Delta H<\Delta E$

Formation of $C{O}_2$ from $CO$ is is an exothermic reaction, heat is evolved from the system. i.e. energy is lowered, thus, exothermic reactions occur spontaneously on account of decrease in enthalpy of system.

Thus $\Delta E>\Delta H⟹\Delta H<\Delta E$