Chapter 7.9, Problem 7.72PP

Classify each of the following as exothermic or endothermic:

a. ${\text{C}}_{\text{3}}{\text{H}}_{\text{8}}\left(g\right){\text{ + 5O}}_{\text{2}}\left(g\right)\stackrel{\text{Δ}}{\to }{\text{3CO}}_{\text{2}}{\text{ + 4H}}_{\text{2}}\text{O}\left(g\right)\text{ + 2220kJ}$
b. $\text{2Na}\left(s\right)+{\text{ Cl}}_{\text{2}}\left(g\right)\to \text{2NaCl}\left(s\right)+\text{ 819kJ}$
c. ${\text{PCl}}_{\text{5}}\left(g\right)+\text{67kJ}\to {\text{PCl}}_{\text{3}}\left(g\right)+{\text{Cl}}_{\text{2}}\left(g\right)$