In a campfire, 5 kg of wood was burnt. It took 3 hours for the wood to undergo complete combustion. The heat produced on complete combustion was 1,05,000 kJ. Calculate the calorific value of this wood.
Mention the formula used
Answers
Answer:
The calorific value of fuel is the amount of heat produced by the complete combustion of 1 kg of fuel.
Heat produced by 4.5 kg of fuel =180000 kJ.
Heat produced by 1 kg fuel =
4.5
180000
=40000 kJ/kg.
Hence, the calorific value of the fuel is 40,000 kJ/kg.
Given:-
→ Amount of heat produced = 1,05,000 kJ
→ Amount of wood [fuel] burnt = 5kg
→ Time taken = 3 hours
To find:-
→ Calorific value of the wood.
Solution:-
We know that :-
Calorfic value of a fuel :-
= Amount Heat produced/Mass of fuel burnt
= 105000/5
= 21000 kJ/kg
Thus, calorific value of the wood is 21000 kJ/kg .
[Note : In this problem, there is no use of time taken by the wood to undergo complete combustion.]
Some Extra Information:-
The amount of heat produced on complete combustion of 1kg of a fuel is called it's calorific value. The efficiency of a food/fuel mainly depends on it's calorific value. If it's calorific value is high, then efficiency is also high.
It's unit it is kJ/kg [Kilojoules per-kilogram]
The calorfic value of some common fuels are :-
• Cow Dung = 8000 kJ/kg
• Petrol = 45000 kJ/kg
• Diesel = 45000 kJ/kg
• Biogas = 40000 kJ/kg
• Coal = 33000 kJ/kg
• LPG = 55000 kJ/kg