Calculate the heat of formation of acetic acid form the following date:
a. `CH_(3)COOH(l) +2O_(2)(g) rarr 2CO_(2)(g) +2H_(2)O(l)DeltaH^(Theta) =- 200.0kcal`
b. `C(s) +O_(2) (g) rarr CO_(2)(g), DeltaH^(Theta) =- 94.0 kcal`
c. `H_(2)(g) +(1)/(2)O_(2)(g) rarr H_(2)O(l), DeltaH^(Theta) =- 68.0 kcal`

Explanation

The required equation is
`2C(s) +2H_(2)(g) +O_(2)(g) = CH_(3)COOH(I),DeltaH^(Theta) = ?`
This equation can be obtained by multiplying equatioon (iii) by `2` and also equation (c ) by `2` and adding both and finally subtracting equation (a).
`[2C +2O_(2) +2H_(2)O +O_(2) - CH_(3)COOH(l) - 2O_(2) rarr 2CO_(2) +2H_(2)O - 2CO_(2) - 2H_(2)O]`
`DeltaH^(Theta)(CH_(3)COOH(l)) = 2 xx (-94.0) +2 xx (-68.0) -(-200.0)`
`=- 188.00 - 136.0 + 200.0`
`=- 324.0 + 200.0`
`=- 124.0 kcal`