Question

Heats of combustion of ${CH}_4,C_2{H}_6,C_2{H}_4$ and $C_2{H}_2$ is $-212.8,-373.0,-337.0$ and $-310.5$ $kcal$ respectively at the same temperature. The best fuel among these gases is:

• A. ${CH}_4$
• B. $C_2{H}_6$
• C. $C_2{H}_4$
• D. $C_2{H}_2$

Answer 1

Answer: (A)

${CH}_4$

The fuel should have high calorific value. Higher the calorific value, best will be the fuel. Calorific value is the total energy released as heat when complete combustion of a substance occurs with oxygen under standard conditions. As the heat of combustion of ${CH}_4$ is less negative the ${CH}_4$ will be the best fuel among the following.