Which among the following fuels given has the highest calorific value ?
APetrol
BCarbon
CEthanol
DHydrogen
Answer:
D. Hydrogen
Read Explanation:
Calorific Value Comparison (Approximate Values per kg)
Calorific value is the amount of heat energy released on the complete combustion of a unit mass of fuel. When comparing the given fuels, Hydrogen stands out significantly.
Fuel | Approximate Calorific Value (kJ/kg) |
A) Petrol (Gasoline) | 44,000−46,000 |
B) Carbon (Coal/Anthracite) | 25,000−33,000 |
C) Ethanol | 26,000−30,000 |
D) Hydrogen | 120,000−150,000 |
Hydrogen has the highest calorific value of all common fuels because its molecule is very light (H2) and the combustion reaction produces water, which is highly exothermic, meaning it releases a large amount of energy per unit mass.