The specific heat capacity of a substance is the amount of heat required to raise one gram of the substance by one degree Celsius. Water, for example, has a specific heat capacity of 4.18 . This means to heat one gram of water by one degree Celsius, it would require 4.18 joules of energy.
s = specific heat capacity (sometimes represented by the letter c, or Cs)
q = heat
m = mass
Δ T = change in temperature
Specific Heat Capacity Formula Questions:
1. What is the specific heat capacity of iron if it takes 125 J of heat to raise 111 grams by 2.5 degrees Celsius?
2. What is the specific heat capacity of aluminum if it takes 2500 J to raise 150 grams from 10°C to 28.5°C?
In this problem the change in temperature must be determined by taking the final temperature (Tf) minus the initial temperature (Ti).
Δ T = Tf - Ti
Δ T = 28.5°C – 10°C
Δ T = 18.5°C
Continue by solving the equation for specific heat capacity.
When the temperature of an object increases it has gained energy. The amount of energy depends on:
- The temperature change, θ
- The mass of the object, m
- The specific heat capacity, c
The specific heat capacity is different for different materials. It is the energy needed to increase the temperature of 1 kg of the material by 1°C and is measured in J/kg °C.
Energy = mass × specific heat capacity × temperature change
E = m × c × θ
Build Your Understanding - This is how to measure the specific heat capacity of a metal block:
- Measure the temperature and the mass of the block, m.
- Use an electric heater to raise the temperature of a metal block. Energy supplied, E = power × time.
- Measure the temperature of the block at the end of the heating time and calculate the increase in temperature θ.
- Calculate the specific heat capacity of the metal,
c = E
m × θ
The video below explains more about specific heat capacity