Question
Question: How is the heat capacity of a body related to the specific heat capacity of its substance?...
How is the heat capacity of a body related to the specific heat capacity of its substance?
Solution
Hint
Heat capacity is a property that relates to the body as a whole. Whereas, specific heat capacity deals with a unit mass of the concerned body.
Complete step by step answer
We know that the heat capacity of a body is a physical parameter defined as the quantity of energy required to change the temperature of a given material by 1 unit. The SI unit is given as Joules/Kelvin.Whereas, the specific heat capacity is the amount of energy required to change the temperature by 1 unit of material of 1kg mass. So, the more the specific heat, the more is the amount of energy required to change a body’s temperature. The SI unit of the specific heat capacity is J/kg K. This is the basic difference between the two according to their definitions.
Now, let’s look at the mathematical expression by which they are defined:
Q=mCΔT
Here, Q is the heat capacity, m is the mass, C is the specific heat capacity, and ΔT is the change in temperature that the body experiences. We can also see that the heat capacity is directly proportional to the specific heat capacity.
Additional Information
Specific heat and heat capacity find various uses in thermodynamics and our daily lives. For example, the utensils we use in the kitchen are made of materials with low specific heat capacity so that less energy is required to raise the temperature to a point ideal for cooking.
Note
Because of the similar terminology, it is easy to get confused between both quantities. To make it easy to recall, one can remember that specific implies ‘specific mass of the substance’ and hence, identify the two parameters better.