Calculate the enthalpy change for the reaction
`CH_2 = CH_2(g) + H_2(g0 to CH_3 - CH_3(g)`.
The bond energies of `C - C , C - H, H- H` and C = C bonds are 83 kcal, 99 kcal 104 kcal and 145 kcal respectivley.

Explanation

To calculate the enthalpy change (ΔH) for the reaction:

\[ \text{CH}_2= \text{CH}_2(g) + \text{H}_2(g) \rightarrow \text{CH}_3 - \text{CH}_3(g) \]

we will use the bond energies provided for the various bonds involved in the reaction.

### Step-by-Step Solution:

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