Question

calculate the heat of reaction δh for the following reaction: 2 hcl(g) + br₂(g) → 2 hbr(g) + cl₂(g) you can find a table of bond energies by using the data button on the aleks toolbar. round your answer to the nearest kj/mol. try again your answer is incorrect.

Explanation:

Step1: Recall Bond Energy Formula

The enthalpy change of a reaction ($\Delta H$) using bond energies is calculated as:
$\Delta H = \sum (\text{Bond energies of reactants broken}) - \sum (\text{Bond energies of products formed})$

Step2: Identify Bonds in Reaction

Reaction: $2\text{HCl}(g) + \text{Br}_2(g)
ightarrow 2\text{HBr}(g) + \text{Cl}_2(g)$

• Reactants: $2$ $\text{H-Cl}$ bonds, $1$ $\text{Br-Br}$ bond.
• Products: $2$ $\text{H-Br}$ bonds, $1$ $\text{Cl-Cl}$ bond.

Step3: Look Up Bond Energies (Typical Values)

• $\text{H-Cl}$: $431$ kJ/mol, $\text{Br-Br}$: $193$ kJ/mol,
• $\text{H-Br}$: $366$ kJ/mol, $\text{Cl-Cl}$: $243$ kJ/mol.

Step4: Calculate Energy for Reactants

Reactants: $2 \times 431 + 193 = 862 + 193 = 1055$ kJ/mol.

Step5: Calculate Energy for Products

Products: $2 \times 366 + 243 = 732 + 243 = 975$ kJ/mol.

Step6: Compute $\Delta H$

$\Delta H = 1055 - 975 = 80$ kJ/mol.

Answer:

$\boxed{80}$ (kJ/mol)