Question

Define 1 Kilocalorie of heat?

Answer 1

Hint : Calorie can be defined as a unit of energy. It is the amount of heat required to raise the temperature of a quantity of water by one degree Celsius. Energy is often expressed as calorie, although the S.I unit of energy is Joule

Complete Step By Step Answer:
The small calorie or simply calorie is defined as the amount of heat required to raise the temperature of one gram of water by one degree Celsius.
The Kilocalorie or large calorie is the amount of heat required to raise the temperature of one kilogram of water by one degree Celsius. It is widely used in nutrition. And is mainly regarded as a unit of food energy.
One kilocalorie is equal to $1000$ calories.
$1Kcal = 1000cal$
Since the S.I unit of heat is Joule , one calorie is equal to $4.184$ Joules
$1cal = 4.184J$
Also, $1Kcal = 4.184KJ$ .

Additional Information:
Kilocalories unit is used by nutritionists in order to characterize the energy-producing potential in food. Kilocalories is a unit of heat which is equal to the amount of heat required to raise the temperature of one kilogram of water by one degree at one atmosphere pressure. Important thing to note is that the Calorie we refer to in food is Kilocalorie only.

Note :
We have seen that kilocalorie is actually a unit of food energy only, widely used by nutritionists. In nutrition, kilocalorie and calorie equals the same amount of energy. The term small calorie is rarely used today. In order to convert Kilocalorie into Kilojoule, just multiply by $4.184$