Question

Why is the specific heat different for different substances?

Answer 1

1. We know that the temperature of a body is directly proportional to the average kinetic energy of particles of the body.

2. The molecules of the system have different forms of energies. The total energy of the system is called internal energy of the system.

3. When we supply heat energy to the system, the heat energy given to it will be shared by the molecules among the various forms of energy.

4. This sharing will vary from substance to substance.

5. The rise in temperature is high for a substance, if the maximum share of heat energy is utilised for its linear K.E.

6. This sharing of heat energy also varies with temperature. That is why the specific heat is different for different substances.

Answer 2

Specific heat, which is also known as thermal capacity, is the amount of heat required to raise the temperature of one gram of substance by 1Degree.To compute specific heat, you would use the equation:

Q = cm Δt ,where Q is the amount of heat added, c is the specific heat, m is the mass of the substance, and Δt is the temperature change.

From this equation, we can see why different substances have different specific heats. Each substance will have a different mass, so when the amount of heat and the change in temperature are held constant, the only variable is the mass. Therefore, because mass is the only variable, so because substances have different masses, they will have different specific heats.