Heat capacity is the heat required to increase an object temperature by one degree. Heat gain or loss results in changes in temperature, state, and performance of the work. Heat is a transfer of energy. The heat capacity of a defined object is usually expressed in joules or calories and temperature in Kelvin or Celsius.
Formula for Heat Capacity
The heat Capacity formula is expressed as the product of mass, specific heat, and change in the temperature which is mathematically given as:
Q = mcΔT
Where,
- Q is the heat capacity in Joules
- m is the mass in grams
- c is the specific heat of an object in J/g °C
- ΔT is the change in the temperature in °C
The heat capacity problem can be applied to calculate the heat capacity, mass or temperature difference of any given substance.
Heat Capacity is described in Joule per Kelvin (J/K).
Please note that in Heat capacity, we consider the specific amount of mass and that mass can be any amount.
Solved Examples
Example 1
Determine the heat capacity of copper of mass 70 g and the temperature difference is 20oC if 300 J of heat is lost.
Solution:
Given parameters are,
Mass m = 70 g,
Temperature difference T = 20oC,
Heat lost Δ Q = 300 J
the Heat capacity formula is given by
Q = mc ΔT
c= 300 / 20
c= 15 J/oC
Example 2
Determine the heat capacity of 3000 J of heat is used to heat the iron rod of mass 10 Kg from 20oC to 40oC.
Solution:
Given parameters are
Mass m = 10 Kg,
Temperature difference Δ T = 20oC,
Heat lost ΔQ = 3000 J
The Heat capacity formula is given by
Q = mc ΔT
c= 3000 / 20
c= 150 J/oC
Comments