Question

What do you understand by the following statements?
i) Heat capacity of the body is 60JK-1.
ii) The specific heat capacity of lead is 130JKg-1K-1.

Answer 1

The heat capacity of an object is given by:
$C = \dfrac{{\Delta Q}}{{\Delta T}}$ ($\Delta Q$ is the amount of heat that is added to the object, $\Delta T$ is the temperature rise)
The specific heat capacity of a body is given by:
$c = \dfrac{C}{M} = \dfrac{1}{M}\dfrac{{dQ}}{{dT}}$ ( dQ represents the amount of heat needed to raise the temperature of the sample by a small increment dT).

Complete step by step solution:
Let’s define the heat capacity and specific heat capacity of a body.
Heat capacity of a body: Heat capacity or thermal capacity is a physical property of matter around us. In other words heat capacity is the heat supplied or transferred to a given mass of object to bring about a unit change in its temperature. The SI unit of heat capacity is joules per Kelvin. Heat capacity is an extensive property of a body which means that it changes with the change in matter in the surroundings.
Therefore, the heat capacity of a body is 60JK-1, meaning that the body requires 60J of energy in order to increase the temperature to 1K.

Specific heat capacity of a body: It is the amount of energy added to mass of a body in order to change the temperature of a body to 1 unit .The SI unit of specific heat capacity is joules per unit kilogram Kelvin.
Thus, a specific heat capacity of lead is 130 JKg-1K-1, means that 1 kg of lead requires 130J of heat energy to raise its temperature through 1K.

Note: When we heat two different metallic bodies, each of the two have different amounts of heat and both have different temperatures, this is due to the specific heat of the two metals. Each of the two metals raise temperature according to their mass and absorption of heat.