Question

Hydrogen and iodine gases react to produce hydroiodic acid according to the reaction.
H2 + I2 → 2HI
How much total bond energy in kJ/mol is in the products of the reaction?
A) 448
B) 594
C) 297
D) 453

Answer 1

To calculate the total bond energy in the products of the reaction \( H_2 + I_2 \rightarrow 2HI \), we need to know the bond energies of the bonds broken and formed in the reaction.

1. **Bonds in Reactants:**
- In the reactants, we have 1 mole of \( H_2 \) (which has 1 H-H bond) and 1 mole of \( I_2 \) (which has 1 I-I bond).
- The bond energies are approximately:
- \( H-H \): ~432 kJ/mol
- \( I-I \): ~151 kJ/mol

2. **Bonds in Products:**
- In the products, we have 2 moles of \( HI \) (which has 2 H-I bonds).
- The bond energy for \( H-I \) is approximately 298 kJ/mol.

Now, we can calculate the total bond energy for the products:

\[
\text{Total Bond Energy in Products} = 2 \times \text{(Bond Energy of } H-I \text{)}
\]
\[
= 2 \times 298 \text{ kJ/mol} = 596 \text{ kJ/mol}
\]

Since none of the options provided (A-D) exactly match this value, I'm inclined to say it seems to be an estimation and could potentially be sourced from an average or rounded figure in available literature.

However, since the closest approximate value to 596 kJ/mol would be considered, but no option of \( 596 \text{ kJ/mol} \) is given.

Therefore, according to the choices provided, the value of \( 594 \text{ kJ/mol} \) (Option B) would be the most reasonable approximation, assuming rounding variations in bond energies.

So, the answer is:

**B) 594 kJ/mol**