Subsubsection Specific Heat
In the discussion of sensible heat and latent heat, you may have noticed that it takes only 16 BTU to raise the temperature of 1 pound of ice from 0 °F to 32 °F that is, only 1/2 BTU for each degree of rise in temperature. However, we know that it takes 1 BTU (on the average) to raise the temperature of the same amount of water 1 °F. This difference occurs because the specific heat of water is about twice the specific heat of ice.
Specific heat is a thermal property of matter that must be determined experimentally for each substance. In general, we may say that specific heat is the property of matter; this explains the reason that equal quantities of thermal energy added to two different substances will not necessarily produce the same temperature rise, even when no change of state is involved. The specific heat of a substance is defined as the quantity of heat required to raise the temperature of unit mass of the substance 1 °F. For most engineering applications, specific heat is expressed in BTU per pound per degree Fahrenheit. In metric systems of measurement, specific heat is expressed in calories per gram per degree Celsius. Even though the units of measurement are different in the different systems, the numerical value of specific heat for any given substance is the same in all systems. The specific heat of water is 1.00 in all systems.
