Calculating Energy Changes In Matter:
The following symbols are used in heat calculations:
The law of conservation of energy tells us that heat lost by one quantity of matter must be gained by another. As a quantity of matter gains heat energy, its temperature will increase based on its individual specific heat.
- Δ = the Greek letter "delta" representing change in
- H = Enthalpy, which we will think of as heat
- ΔH = Change in Enthalpy - or change in heat.
- q = Heat gained or lost. This is very similar to ΔH
- m = Mass
- T = Temperature
- Cp = Specific Heat NOTE: s is often used as a symbol for specific heat.
Specific heat is the heat required to raise the temperature of one gram of a substance by one Celsius degree.
Heat transfer is expressed by the equation q = m(ΔT)Cp
This equation is used whenever a substance
changes heat content without changing phase.