The heat liberated from the combustion of 0.5 g of carbon raised the temperature of 2000 g of water from `24^(@)C` to `26^(@)C.` The heat of the combustion of carbon is

Options

A. `-4 kcal`
B. `-8 kcal`
C. `- 62 kcal`
D. `- 96 kcal`

Explanation

The amount of heat liberated by `0. 5 g of C = ms Delta t = 2000 xx 1 xx (26 - 24) = 400 cal = 4 kcal `
Colorific value `= ( 4 kcal xx 1)/( 0.5) = 8 kcal per g therefore ` Heat of combustion `=- 8 xx 12 =- 96` kcal per mole