Bond energies can be obtained by using the following relation: `DeltaH (reaction) = sum`Bond energy of bonds, broken in the reactants `-sum` Bond energy fo bonds, formed in the products
Bond enegry depends on three factors:
a. Greater is the bond length, lesser is the bond enegry.
b. Bond energy increases with the bond multiplicity.
c. Bond enegry increases with electronegativity difference between the bonding atoms.
Use the bond enegries to estimate `DeltaH` for this reaction:
`H_(2)(g) +O_(2)(g) rarr H_(2)O_(2)(g)`
`{:("Bond","Bond energy"),(H-H,436 kJ mol^(-1)),(O-O,142 kJ mol^(-1)),(O=O, 499kJ mol^(-1)),(H-O,460kJ mol^(-1)):}`

Options

A. `-127 kJ`
B. `-109 kJ`
C. `-400 kJ`
D. `-800 kJ`

Explanation

To estimate the change in enthalpy (ΔH) for the reaction \( H_2(g) + O_2(g) \rightarrow H_2O_2(g) \) using bond energies, we can follow these steps:

### Step 1: Identify the bonds broken in the reactants
In the reaction, we have:
- One \( H-H \) bond in \( H_2 \)
- One \( O=O \) bond in \( O_2 \)

### Step 2: Identify the bonds formed in the products
...