Answer
The change in energy (ΔE) for the given reaction is 194 kJ/mol.
Work Step by Step
To predict the change in energy (ΔE) for the given reaction using bond energies, we need to calculate the energy required to break the bonds in the reactants and the energy released when the bonds in the products are formed.
The reaction is:
$CH_{4}(g) + H_{2}O(g) \rightarrow CO(g) + 3H_{2}(g)$
The bond energies involved are:
- C-H bond energy: 413 kJ/mol
- O-H bond energy: 463 kJ/mol
- C=O bond energy: 799 kJ/mol
- H-H bond energy: 436 kJ/mol
To calculate ΔE, we need to consider the bond breaking and bond forming processes:
Bond breaking:
- 4 C-H bonds are broken: 4 × 413 = 1652 kJ/mol
- 2 O-H bonds are broken: 2 × 463 = 926 kJ/mol
Total energy required for bond breaking = 1652 + 926 = 2578 kJ/mol
Bond forming:
- 1 C$\equiv$O bond is formed: 1076 kJ/mol
- 3 H-H bonds are formed: 3 × 436 = 1308 kJ/mol
Total energy released from bond forming = 1076 + 1308 = 2384 kJ/mol
The change in energy (ΔE) for the reaction is the difference between the energy required for bond breaking and the energy released from bond forming:
ΔE = Energy required for bond breaking - Energy released from bond forming
ΔE = 2578 kJ/mol - 2384 kJ/mol = 194 kJ/mol
Therefore, the change in energy (ΔE) for the given reaction is 194 kJ/mol.
