For the reaction

CHEMISTRY · Single correct · A Level · Chemistry · Energetics · Energetics

Problem

For the reaction

2\,\text{Al}(s)+3\,\text{Cl}_2(g)\rightarrow 2\,\text{AlCl}_3(s)

, the enthalpy change is

\Delta H=-704\,\text{kJ}

for the equation as written. A student reacts

5.40\,\text{g}

of Al with

12.7\,\text{g}

\text{Cl}_2

at constant pressure. Which of the following is closest to the heat released? (a)

-70\,\text{kJ}

(b)

-28\,\text{kJ}

(c)

-42\,\text{kJ}

(d)

-63\,\text{kJ}