Use the bond energies provided to estimate ΔH°_rxn for the reaction below. PCl₃(g) + Cl₂(g) → PCl₅(l) ΔH°_rxn= ?
Bond Bond Energy (kJ/mol)
Cl-Cl 243
P-Cl 331

Question

Use the bond energies provided to estimate ΔH°_rxn for the reaction below. PCl₃(g)+ Cl₂(g)→ PCl₅(l)ΔH°_rxn= ? Bond Bond Energy (kJ/mol) Cl-Cl 243 P-Cl 331

Quizplus · Accepted Answer

The reaction involves breaking one Cl-Cl bond and forming two P-Cl bonds. The energy required to break the Cl-Cl bond is +243 kJ/mol (endothermic process), and the energy released by forming two P-Cl bonds is -2(331) kJ/mol = -662 kJ/mol (exothermic process). The net change in energy (ΔH°rxn) is the sum of these values: ΔH°rxn = 243 kJ/mol - 662 kJ/mol = -419 kJ/mol.

Use the Bond Energies Provided to Estimate ΔH°rxn for the Reaction

Use the Bond Energies Provided to Estimate ΔH°_rxn for the Reaction