1.0 Introduction

Gases have variouspropertieswhich we can observe with our senses, including the gaspressure (p),temperature,mass, and the volume (V) which contains the gas. Careful, scientific observation has determined that these variables are related to one another, and the values of these properties determine thestateof the gas.In the mid 1600's, Robert Boyle studied the relationship between the pressure and the volume of a confined gas held at a constant temperature. Boyle observed that the product of the pressure and volume are observed to be nearly constant. (The product of pressure and volume is exactly a constant for anideal gas.) This relationship between pressure and volume is calledBoyle's Lawin his honor.For example,suppose we have a theoretical gas confined in a jar with a piston at the top.the initial state of the gas has a volume equal to 4.0 cubic meters and the pressure is 1.0 kilopascal. With the temperature and number of moles held constant, weights are slowly added to the top of the piston to increase the pressure. When the pressure is 1.33 kilopascals the volume decreases to 3.0 cubic meters. The product of pressure and volume remains a constant (4 x 1.0 = 3 x 1.33333 ).

2.0 Objectivea. Understand Boyles lawb. Determine the relationship between the pressure and volume.

3.0 Course Learning outcomeUpon completion of this course students should be able to:i. Analyse critically the experimental data in relation to the theoretical aspects.ii. Organize appropriately experiments in group according to the standard of procedures.iii. Write critically the appropriate report in group based on the experimental results.

4.0 TheoryBoyles Law states that the pressure of a gas in a container is related to the volume of the gas. In other words, as the volume changes, the pressure changes. For a given amount of a gas at a fixed temperature the pressure of the gas is inversely proportional to the volume. One way to verify this is to graph the inverse of gas volume versus gas pressure.Air,under standard conditions,behaves approximately as an ideal gas.An ideal gas obeys the ideal gas law.PV= nRT=NkBT (1)Here,P is pressure (the unis used in the experiment are kPa).Note that atmospheric pressure under standard conditions is about 101.326 kPa.The volume of the gas is V (measured in ml). Note that 1cc= 1ml. These are the only variable quantities in the experiment.Thus,if air,under the conditions of the experiment,is an ideal gas,PV=constant (2)This is Boyles law.for reference,the other quantities in (1) are n,the number of moles of gas,R, the gas constant,T, the temperature (which is measured on an absolute scale,such as kelvins)N the number of molecules of gas,and kB Boltzmann.s constant.

Question.

a. What is Kelvin Temperature?Close to 300 K

b. Which of the following conditions is the that temperature closer to?human body temperature freezer temperature?Room temperature

c. Describe what is added to the piston to increase the pressure.Increase air volume.

d. Write the formula equation for Boyles lawPV = C

e. Write the equationn for Boyles law in words.The pressure of a gas times its volume is a constant.

f. What are the units of pressure?Kilopascals

g. What are the unit of volume used in the lab?Cubic meters

h. List down the application of boyles law.A practical application illustrating Boyle's Law would be the action of a syringe. When we draw fluids into a syringe, we increase the volume inside the syringe, this correspondingly decreases the pressure on the inside where the pressure on the outside of the syringe is greater and forces fluid into the syringe. If we reverse the action and push the plunger in on the syringe we are decreasing the volume on the inside which will increase the pressure inside making the pressure greater than on the outside and fluids are forced out.A more life dependent example of Boyle's Law is the action of the diaphragm of our body. This is a muscle that is located just below the lungs. When we inhale the diaphragm moves downward allowing the lungs an increased volume. This decreases the pressure inside the lungs so that the pressure is less than the outer pressure. This results in forcing air into the lungs. When we exhale the diaphragm moves upward and decreases the volume of the lungs. This increases the pressure inside the lungs above the pressure on the outside of the lungs so that gases are forced out of the lungs. Of course, all of this is totally automatic and we take this important cycle which is performed hundreds of times a day for granted until we receive a sharp blow to that region that briefly paralyses the diaphragm muscle. We say the wind was knocked out of us, but Boyles Law was not allowed to function.

i. Zip a sandwich bag nearly closed.insert a straw into the opening and blow through the straw to inflate the bag.so that it is a little over half full of air.Completely seal the bag.Describe what happens to the pressure of the air in the bag as you decrease its volume.The air in the bag exerts more pressure.

8.0 Reference

Http://www.grc.nasa.gov/www/k-12/airplane/boyle.html

http://group.chem.iastate.edu/greenbowe/sections/projectfolder/flashfiles/gaslaw/boyles_law_graph.html