The average O-H bond energy in `H_(2)O` with the help of following data.
(1) `H_(2)O(l)rarrH_(2)O(g), Delta H= +40.6 kJ mol^(-1)`
(2) `2H(g)rarrH_(2)(g), DeltaH= -435.kJ mol^(-1)`
(3) `O_(2)(g)rarr2O(g), Delta H= +489.6 kJ mol^(-1)`
(4) `2H_(2)(g)+O_(2)(g)rarr2H_(2)O(l), Delta H= -571.6 kJ mol^(-1)`

Options

A. `584.9 kJ mol^(-1)`
B. `279.8 kJ mol^(-1)`
C. `462.5 kJ mol^(-1)`
D. `925 kJ mol^(-1)`

Answer

C

Explanation

Assuming density of solution is `1g//c c` and specific heat is `4.2 J//gc`
`=msDelta T=100xx4.2xx3`
millimoles of acid neutralized `=5`
`DeltaH= - 100xx4.2xx3xx(1000)/(5)= -2.52xx10^(2)KJ//"mole"`.