The reaction of the combustion of carbon is:
C + O2 --> CO2 dH = -393.5 kJ
As dH is negative the reaction is exothermic and burning one mole of carbon releases 393.5 kJ of heat.
The molar mass of carbon is 12. The combustion of 12 g of carbon releases 393.5 kJ of heat, the heat released when one gram of carbon reacts with oxygen is 393.5/12 = 32.79 kJ
When 4.72 g of carbon reacts with oxygen the heat released is (393.5/12)*4.72 = 154.77 kJ.
The required amount of heat released when 4.72 g of carbon reacts with oxygen in the reaction C + O2 --> CO2 is 154.77 kJ.