Question

use the bond energy values in the table provided to calculate the \\( \delta h \\), in \\( \mathrm{kj} \\), for the reaction:

\\( \mathrm{h}_{2}(\mathrm{~g})+\mathrm{cl}_{2}(\mathrm{~g}) \
ightarrow 2 \mathrm{hcl}(\mathrm{g}) \\)

bond	be (kj/mol)
\\( \mathrm{cl}-\mathrm{cl} \\)	243
\\( \mathrm{h}-\mathrm{cl} \\)	432

report your answer to three significant figures. do not include units in your answer.

Explanation:

Step1: Calculate energy to break bonds

Energy to break \(H - H\) and \(Cl - Cl\) bonds:
\(436+243\) \(= 679\)

Step2: Calculate energy released from forming bonds

Energy released from forming \(2\) \(H - Cl\) bonds:
\(2\times432\) \(= 864\)

Step3: Calculate \(\Delta H\)

\(\Delta H=\) (Energy to break bonds) - (Energy released from forming bonds)
\(\Delta H = 679-864=-185\)

Answer:

\(-185\)