High quality coal (anthracite) is almost pure carbon. The combustion of carbon to carbon dioxide

Question

releases 393 kJ per mol of carbon burnt. If 1.000 kg of anthracite is burnt:
(i) How much heat is released?
(ii) How much ice (in kg) at 273 K could be melted to give water at 273 K using the heat in (i)? (iii)How much ice at 273 K could be melted to give water at 100 °C using the heat in (i)?
(iv) How much ice at 273 K could be melted to give steam at 373 K using the heat in (i)?

Answer 1

C + O2 ==> CO2 +393 kJ/mol = 393 kJ/12 g C.
1. So 393 kJ x (1,000 g/12 g) = ? = approx 33,000 kJ but that's just an estimate.
2. How much heat is required to melt 1 g ice. That's approx 334 J/g ice but you need to use the value in your text/tables. You have about 33,000 kJ. How much ice can you melt with that.
3 & 4. Same thing as 2 but the ice, after metling must raise the T from the melted ice at zero C to 100 C. In 4 you must add enough to raise change the phase from liquid to steam.
Post your work if you need more help.