Chemistry

Problem

Using the average bond energies in the table below, determine

\Delta H_{\mathrm{rxn}}

for the reaction

\mathrm{H_2(g)+Cl_2(g)\;\rightarrow\;2\,HCl(g)}

Bond energies (kJ mol

^{-1}

): H–H = 436; Cl–Cl = 243; H–Cl = 431 a)

+183\ \text{kJ}

+679\ \text{kJ}

-183\ \text{kJ}

+248\ \text{kJ}