Chapter 8.7, Problem 8.10P

How much heat in kilojoules is evolved or absorbed in each of the following reactions?

1. (a) Burning of 15.5 g of propane:

${\text{C}}_3{\text{H}}_8(g)+5{\text{O}}_2(g)\stackrel{}{\to }3{\text{CO}}_2(g)+4{\text{H}}_2\text{O}(l)\Delta H°=-2220\text{kJ}$

1. (b) Reaction of 4.88 g of barium hydroxide octahydrate with ammonium chloride:

$\begin{array}{l}\text{Ba}{(\text{OH})}_2\cdot 8{\text{H}}_2\text{O}(s)+2{\text{NH}}_4\text{Cl}(s)\stackrel{}{\to }\hfill \\ {\text{BaCl}}_2(aq)+2{\text{NH}}_3(aq)+10{\text{H}}_2\text{O}(l)\Delta H°=+80.3\text{kJ}\hfill \end{array}$