7. Energy, Rate and Equilibrium

Consider the following equation:

Determine the bond enthalpy value for the F–S bond.

Use the bond energies to estimate the enthalpy of reaction for the combustion of 5 moles of acetylene:

In photosynthesis, green plants convert carbon dioxide and water into glucose (C₆H₁₂O₆) according to the following equation:

6 CO₂(g) + 6 H₂O(l) → C₆H₁₂O₆(aq) + 6 O₂(g)

a. Estimate ∆H for the reaction using bond dissociation energies from Table 7.1. Give your answer in kcal/mol and kJ/mol. (C₆H₁₂O₆ has five C―C bonds, seven C―H bonds, seven C―O bonds, and five O―H bonds).

Acetylene (H–C≡C–H) is the fuel used in welding torches.

b. Estimate ∆H for this reaction (in kJ/mol) using the bond energies listed in Table 7.1.

Nitrogen in air reacts at high temperatures to form NO₂ according to the following reaction: N₂ + 2 O₂ → 2 NO₂

b. Estimate ∆H for this reaction (in kcal and kJ) using the bond energies from Table 7.1.