For the reaction:
`2H_(2)(g) +O_(2)(g) rarr 2H_(2)O(g), DeltaH =- 571 kJ`
bond enegry of `(H-H) = 435 kJ` and of `(O=O) = 498 kJ`. Then, calculate the average bond enegry of `(O-H)` bond using the above data.

Options

A. `484 kJ`
B. `-484 kJ`
C. `271 kJ`
D. `-371 kJ`

Explanation

`2(H-H) +O=O rarr 2(H-O-H)`
`DeltaH^(Theta) = sum(BE) ("reactants") -sum(BE) ("products")`
`-571 =[2 xx 435 +498] - 4 xx (BE)_(O-H)`
`(BE)_(O-H) = (2 xx 435 + 498 +571)/(4) = 484 kJ`