a) Classify heat carriers giving examples, natural and derivatives, of eacn type. b) A sample of coal has the following composition by mass carbon 75%, hydrogen 6%, oxyEen 8%, nitrogen 2.5\%, Sulphur 1.5% and ash 7%. Calculate the H.C.V and LCV given that the heats of combustion for carbon, hydrogen and sulphur are in kJ/kg. -33800 ;144000 and 9270 and heat of vaporization of water is 2466kJ/kg. Dont are pi for oryigen