DRAFT: This module has unpublished changes.

Purpose:

The purpose of this lab is to determine how pressure, temperature, and volume are related in a gas.

 


Introduction:


The distance between particles in gases are very large which allows them to be measurably compressed. Gas particles are able to move freely, bouncing off each other and filling their container. The pressure of a gas is related to how frequently the molecules collide into surfaces. One example of how to change the pressure can be observed when the volume is changed. If the volume is increased, the walls of the container are farther apart, taking it longer for the molecules to go from one wall to the other. The temperature affects the speed of the molecules so therefore also affects the rate at which the gas molecules collide into surfaces. The higher the temperature, the faster the gas molecules will move. Adversely, the lower the temperature, the slower the gas molecules will move. This property lead to the discovery of absolute zero. The colder something becomes, the slower the molecules move, thus the temperature at which all motion stops, must be the coldest temperature possible (absolute zero).

 

Lab 29 includes observing the behaviors of gas through twi different laws; Boyle's Law in part 1 and Guy-Lussac's Law in part 2. Boyle's Law describes the inverse relationship between the absolute pressure and volume of a gas. Pressure times volume is equal to a constant K (p x v = K). This graph would appear to be exponential. However, when one rearranges this equation to pressure equals the constant divided by volume (p= K/v), the graphs appears to be linear. This equation shows the inverse relationship described in Boyle's Law.

 

Guy-Lussac's Law states the pressure of a gas of fixed volume and fixed mass is directly proportional to the gas's absolute temperature. This law can be expressed as p=KT so pressure equals a constant times temperature. Clearly, pressure and temperature have a direct relationship.

DRAFT: This module has unpublished changes.