Question

What is calorific value ? give an example for
each of the combustible stubstance which has higher
and lower Calorific value.​

Answer 1

Answer:

Higher and lower calorific values (=heating values) for some common fuels - coke, oil, wood, hydrogen and others. ... The resulting energy value divided by grams of fuel burned gives the energy content (in J/g).

Calorific value is the amount of energy released or produced when 1 kg of fuel burns or any other substance is burnt in the presence of oxygen and the products of combustion are cooled to STP. Its SI unit is kJ/kg.

For petrol it is 45.8 MJ/kg. From the above explanation we can say that LPG has the highest calorific value.

Goutel suggested the following formula from calculating the higher calorific value when the percentage proximate analysis of fuel is known. The formula is, cal. value = 343.3 x fixed carbon % + α x % volatile matter kJ/kg. Goutel formula is unreliable for fuels having high percentage in oxygen.

The amount of heat energy produced on complete combustion of 1 kg of a fuel is called its calorific value. The calorific value of a fuel is expressed in a unit called kilojoule per kg (kJ/kg). Calorific values of some fuels are given in Table. (THIS IS FOR CLASS 8)

Explanation:

Answer 2

Answer:

Calorific value is the amount of energy released or produced when 1 kg of fuel burns or any other substance is burnt in the presence of oxygen and the products of combustion are cooled to STP. Its SI unit is kJ/kg.

Higher and lower calorific values (=heating values) for some common fuels - coke, oil, wood, hydrogen and others. ... The resulting energy value divided by grams of fuel burned gives the energy content (in J/g).