Heat and Temperature
Heat and temperature are two different entities.
Heat is a form of energy and is created by the movement of tiny particles within a substance. So the heat energy within, let’s say a cup of tea, is determined by the speed of the molecules and atoms within the tea itself. This heat energy is measure in Joules (J).
Temperature is similar to heat energy. Temperature is defined as the average kinetic energy of molecules and atoms in a system, and thus it determines how hot or cold a substance is. Temperature is measured in degrees Celsius.
Specific Heat Capacity
The specific heat capacity of a substance is the amount of energy required to heat that substance by 1 degree Celsius. This is an important definition to remember.
You need to use this equation and be able to rearrange it.
Remember: You need to insert the DIFFERENCE in temperature into this equation, it is a common mistake to not calculate the difference in temperature before inserting into this equation.
Specific Latent Heat
Different substances require different amounts of heat energy to change the state of the substance, be that from solid to liquid, liquid to gas and vice versa.
A change from solid to liquid is called fusion.
A change from liquid to gas is called vaporisation
The specific latent heat is the heat energy required to change the state of a substance.
Eh = ml
This graph shows the points where a substance changes state.
Key Points!
-
Heat and Temperature Definitions
Heat is a form of energy and is created by the movement of tiny particles within a substance.
Temperature is defined as the average kinetic energy of molecules and atoms in a system, and thus it determines how hot or cold a substance is.
-
Specific Heat Capacity
The specific heat capacity of a substance is the amount of energy required to heat that substance by 1 degree Celsius.
Eh = cm(delta)T
-
Specific Latent Heat
A change from solid to liquid is called fusion.
A change from liquid to gas is called vaporisation
The specific latent heat is the heat energy required to change the state of a substance.
Eh = ml