The Changes of Heat in Calorimetry

Summary The purpose of this experiment is to learn how heat flows into and through an unknown substance while using a calorimeter to measure the temperature. In this set of experiments we will focus our attention upon one particular area of thermodynamics, calorimetry, a technique used to measure heat flow into and out of matter. This is really simple procedure. The unknown metal is placed into a container called a calorimeter that separates it from everything else. As changes occur, we can follow the movement of heat from one portion of the matter to another by the temperature changes. The container we use as a calorimeter should insulate the metal, it should prevent matter from entering or exiting once our measurement has begun, and it should allow for easy measurement of temperature changes. A reasonable calorimeter can be constructed from a pair Styrofoam cups with lid on top to limit heat transfers into and out of the cups.

Introduction
The amount of heat, Q, required to raise the temperature of a solid body at constant pressure depends on the change in temperature, ∆T, of the body, its mass, m, and a characteristic of the material forming the body called its specific heat, C. This relationship is expressed by the equation Q = mC∆T and the dimensions of C are thus heat per unit mass per unit temperature change. The values of C do depend on temperature with those of the unknown metal. Specific heat can be considered to be the amount of heat required to raise the temperature of one gram of the substance by 1°C. To raise the temperature of 1g of water by 1°C, 4.18 joules of heat must be added to the water. The process of measuring quantities of heat exchanged is called calorimetry. The specific heat of a metal can readily be measured in a calorimeter. A calorimeter is simply a container with insulating walls, made so