In the given reaction, C2H4(g)+3O2(g)⟶2CO2(g)+2H2O(l) ∆H=−1410.0kJ For ideal gas, ∆H=∆U+RT(∆ng) where, R=8.314J∕molK T=298K ∆ng= number of gaseous products - number of gaseous reactants =2−4=−2 ∴−1410=∆U+[8.314×298(−2)] ∆U=−1405.045kJ ∼eq−1405.05kJ Now, ∆H−∆U=−1410−(−1405.05)=−4.95kJ