Calorimetry - Derived from calor which means heat (Latin) and metry which means to measure (Greek).

Calorimeter - A device used to measure the temperature change of a reaction in order to determine the heat flow of a reaction.  This device is generally has a reaction area surrounded by water in which a stirrer and a thermometer are immersed.  The heat given off or absorbed by the reaction affects the temperature of the surrounding water in which the heat is kept evenly distributed with the stirrer.  The thermometer measures the change in temperature of the water which can be converted to find the change in heat of the system.

When no work is done by or on a system, then the internal energy of the system is equal to the heat of the system.  If this is the case, then all the heat that enters or leaves the system will effect the temperature of the system, and the change in heat can be measured by measuring the change in temperature.  

The system can be controlled so that no work is done by restricting the system to a fixed volume:

The following equation can be used to calculate the heat given off or absorbed in a reaction:

• q = heat

• m = mass

• c = specific heat

• T = change in temperature

NOTE: The specific heat of water is 4.184 J/g-K

Suppose a heated metal is immersed in water.  The heat lost by the metal would be equal to the heat gained by the water:

As long as we know the masses and the T for the metal and the water, we could calculate the specific heat for any metal by simply rearranging the equation to solve for c_metal.  q = mcT can be used to relate the loss/gain of heat in many reactions.

Next:  "Enthalpy"