Question

1 g of graphite is burnt completely in excess oxygen at 298K and 1 atmospheric pressure in a bomb calorimeter. During the reaction, the temperature raises from 298K to 299K. If the heat capacity of the bomb calorimeter is 20.7 kJ K\(^{-1}\), what is the enthalpy of combustion of C(gr)? (Atomic mass of carbon is 12 g mol\(^{-1}\))

• A. -248 kJ mol\(^{-1}\)
• B. +236 kJ mol\(^{-1}\)
• C. -236 kJ mol\(^{-1}\)
• D. +246 kJ mol\(^{-1}\)
• E. -268 kJ mol\(^{-1}\)

Hint:

Always remember that combustion is an exothermic process, so the enthalpy change (\(\Delta H\)) must be negative.
This immediately eliminates options (B) and (D).

Answer 1

The Correct Option is A