Question

For the reaction PCI5(g) → PCl3(g) + Cl2(g)
(1) ΔΗ = ΔΕ
(2) ΔΗ > ΔΕ
(3) ΔΗ < ΔΕ
(4) Can't predicted​

Answer 1

Answer:

As the given reaction is the decomposition reaction of PCl5 and normally all the decomposition reaction are endothermic which requires energy to break the bond. Hence enthalpy of reaction is positive (∆H) > 0 or positive .

In the given reaction 1 mol of PCl5 gives the 2 mol of gaseous product. This suggests that there is the increases in the randomness or the entropy of reaction and hence can say that (∆S) > 0 or positive .