Portage Learning CHEM 108CHEM MODULE 3.

Gas Laws Gases are often formed as a product of or are used as a reactant in a chemical reaction. These materials (gases) have some special properties and are subject to some special calculations in chemistry. Gases (think of air as an example) are very light, are easily expandable, are easily compressible, and completely fill a container into which they are released. These properties are due to the fact that the individual molecules of the gas are very far apart from one another, are not attracted to one another and are in constant, very rapid motion. This description of gases is known as the kinetic-molecular theory of gases. Due to these properties, the volume of a sample of gas will expand (increase) if the temperature of the gas sample is increased and the volume of a sample of gas will contract (decrease) if the temperature of the gas sample is decreased. [The temperature scale used with gases is the Kelvin (K) scale, which is °C + 273]. [The volume scale used with gases is the liter scale, which is ml/1000]. Also, the volume of a sample of gas will expand (increase) if the pressure on the gas sample is decreased and the volume of a sample of gas will contract (decrease) if the pressure on the gas sample is increased. [The pressure unit we will use with gases is atmosphere (atm) scale, which is mm/760]