What is the use of specific heat here btw i got 2 kj by direct subtracting -393-(-395) 98 eats of these substances are 720 and 505

Lal 20. The heats of combustion of graphite and diamond at 298 K are -393 and -395 kJ/mole respectively. The specific heats of these substances are 720 and 505 J kg Krespectively. Calculate the heat of transformation of graphite into 28. A heat pu 15°C and from the diamond at 273 K. (2-0645 kJ mole 29. Given the 12 [Hint: AH= [-393 -(395) }+ (0-720-0-505) 1000 x (298-273) ]