For which of the following equation will ΔH be equal to ΔU.
H2(g)+12O2(g)→H2O(l)
H2(g)+I2(g)→2HI(g)
2NO2(g)→N2O4(g)
3NO2(g)+O2(g)→2N2O5(g)
ΔH=ΔU+ΔngRT
if Δng =zero; ΔH=ΔU
So, the number of gaseous moles on the reactants and the products side must be the same. This is seen in option b