Question

For gaseous reactions, if $\Delta H$ is the change in enthalpy and $\Delta U$ that in internal energy, then
$\Delta H>\Delta U$ if the number of mole of the products is less than reactants.
If true 1 else 0.

• A. 1

Answer 1

The correct option is A 1
As we know,
$\Delta H=\Delta U+\Delta nRT$
$\Delta n=n_P-n_R$
so
$\Delta U<\Delta H$ only if the number of mole of the reactants is less than that of the products.
$\Delta H>\Delta U$ only if the number of mole of the products is less than that of the reactants.