Enthalpy of combustion of c(graphite)is _393.3 KJ mol -1then for producing 39.3 KJ of heat the amount of carbon required is

Answer 1

You get 393.5 kJ for 12 g C. You want 39.3 kJ; therefore,
(393.5 kJ/12 g C) x #g C = 39.3 kJ.
Solve for #g C.

Answer 2

12