Answer
a. $31.4\text{ J/$^{\circ}$C}$
b. $-1.10\text{ kJ/mol}$
Work Step by Step
a. $\frac{802\text{ kJ}}{1\text{ mol}}*\frac{1\text{ mol}}{16.04\text{ grams}}*\frac{6.79\text{ grams}}{10.8^{\circ}C}=31.4\text{ J/$^{\circ}$C}$
b.
$\Delta E = \frac{-31.4\text{ J}}{1^{\circ}C}*\frac{26.0\text{ grams $C_2H_2$}}{1\text{ mol $C_2H_2$}}*\frac{16.9^{\circ}C}{12.6\text{ grams $C_2H_2$}}=-1.10\text{ kJ/mol}$
