Question

Use the bond energies to answer teh question

H-H=432
H-O=467
O-O=146
O=O=495
Hsmall2 (H-H) combines with Osmall2 (O=O) to become hydrogen peroxide (Hsmall2Osmall2) bonded as such: H-O-O-H. Which option shows the difference in total bond energy between the reactants and the products?

1080
-153
/ce/bond-927
153

Answer 1

To determine the difference in total bond energy between the reactants (H₂ + O₂) and the products (H₂O₂), we can calculate the total bond energy for both sides.

**Calculating the bond energies for reactants:**

1. For H₂ (two H-H bonds):
- Bond energy of H-H = 432 kJ/mol
- Total for H₂ = 432 kJ/mol

2. For O₂ (one O=O bond):
- Bond energy of O=O = 495 kJ/mol
- Total for O₂ = 495 kJ/mol

**Total bond energy of reactants:**
\[ 432 \, \text{kJ/mol} + 495 \, \text{kJ/mol} = 927 \, \text{kJ/mol} \]

**Calculating the bond energies for products:**

For H₂O₂ (H-O-O-H):
1. Two H-O bonds:
- Bond energy of H-O = 467 kJ/mol
- Total for two H-O bonds = \( 2 \times 467 = 934 \, \text{kJ/mol} \)

2. One O-O bond:
- Bond energy of O-O = 146 kJ/mol

**Total bond energy of products:**
\[ 934 \, \text{kJ/mol} + 146 \, \text{kJ/mol} = 1080 \, \text{kJ/mol} \]

**Calculating the difference in total bond energy:**

Now, we can find the difference in total bond energies between reactants and products:

\[ \text{Difference} = \text{Total bond energy of reactants} - \text{Total bond energy of products} \]
\[ \text{Difference} = 927 \, \text{kJ/mol} - 1080 \, \text{kJ/mol} = -153 \, \text{kJ/mol} \]

The difference in total bond energy is **-153 kJ/mol**.

Therefore, the correct answer is:

**-153**