The given equilibrium reaction is:

The given equilibrium reaction is:

$$\text{PCl}_5(g) \rightleftharpoons \text{PCl}_3(g) + \text{Cl}_2(g) \quad \Delta H \text{ positive}$$

This indicates that the forward reaction (decomposition of PCl$_5$) is endothermic (absorbs heat).
Also, the number of moles of gas increases from the reactant side (1 mole of PCl$_5$) to the product side (1 mole of PCl$_3$ + 1 mole of Cl$_2$, totaling 2 moles of gas).