Calorific value and ignition temperature of fuel X are 75 kJ/g and 200C respectively. These values for fuel Y are 50 kJ/g and 750C respectively. On burning, the fuel Y produces only CO2 while fuel X produces CO2 and CO. Which of the two is a better fuel? Give two reasons to support your answer.
Fuel Y is a better fuel due to the following main reasons:
(i) Y has a moderate ignition temperature of 75°C
(ii) As it do not produce any harmful gas (like CO) while burning.
The calorific values of three fuels A, B and C are 33 KJ/g, 150 KJ/g, respectively. A is solid, B is liquid and C is a gas at room temperature. On combustion, both A and B produces carbon dioxide while C explodes forming steam. B and C leave no residue after combustion while A leaves behind some solid residue. Which one of the three fuels is the most ideal? Give two reasons to support your answer.