Question

Using the bond energies provided, calculate the enthalpy if the reaction?

Answer 1

In high school chemistry, the enthalpy change of a reaction can be calculated using bond energies by summing the energies of broken bonds in reactants, summing the energies of bonds formed in products, and then finding the difference of these sums.

Step-by-step explanation:

The subject matter involves calculating enthalpy changes for a chemical reaction using bond energies. The enthalpy of reaction can be estimated by taking the sum of bond energies for all the bonds broken in the reactants and subtracting the sum of bond energies for all the bonds formed in the products. If more energy is released in forming the products than is consumed in breaking the reactants, the reaction is exothermic, which means the enthalpy change (ΔH) is negative. Conversely, if more energy is required to break the reactant bonds than is released upon forming the product bonds, the reaction is endothermic (ΔH is positive).

To perform this calculation, take the following steps:

1. Identify all bonds broken in the reactants and add their bond energies.
2. Identify all bonds formed in the products and add their bond energies.
3. Subtract the energy of bonds formed from the energy of bonds broken to get the enthalpy change (ΔH).

Example:

• The bond dissociation energy for H-H is given as 436 kJ/mol.
• The bond dissociation energy for Cl-Cl is given as some value from the table provided (which is not given here).
• The energy for the H-Cl bond formed will be obtained similarly (which is also not provided).

Using these values, we can use the formula ΔH = Σ bond energies of broken bonds – Σ bond energies of formed bonds to calculate the enthalpy change for the reaction in question.