# IB Chemistry - Boyle's Law Lab Report

Extracts from this document...

Introduction

Boyle's law The relationship between pressure and volume Raw data 1. Average book weight = (1441 + 1439)/2 = 1440 �0.5g 2. The total pressure on the piston equals the pressure from the books plus the atmospheric pressure = 1034g/cm� (it does not have uncertainty because it was given) ? of book Volume (�0.5ml) Mass book(�0.5g) Diameter of syringe (�0.05cm) Total pressure on piston equals the pressure from the books plus the atmospheric pressure (g/cm�) 0 36 0 2.7 1034 1 36 1440 2 30 2880 3 26 4320 4 23 5760 5 20 7200 6 18 8640 Data processing 1. Radius= diameter/2 = 2.7/2 = 1.35 �0.05cm 2. Area of the contact = ?r� = ?*(1. 35 �0.05)� = 5.73 cm� 3. % of uncertainty on Area � r = 0.05/1.35*100 = 3.7% � ? doesn't have uncertainty but r� has 2 r so I need to add uncertainty of 2 r. � 3.7 + 3.7 = �7.4% so the absolute uncertainty is 5.73*7.4% = �0.42 cm� 4. % of uncertainty on Mass of book = 0.5/1440*100 = 0.04% = �0% 5. Pressure = mass(of book)/area = 1440/5.73 = 251g/cm� 6. % of uncertainty on pressure = % of uncertainty on Mass + % of uncertainty on Area + % of uncertainty on the total pressure on the piston equals the pressure from the books plus the atmospheric pressure = 0 + 7 + 0 = �7% 7. ...read more.

Middle

If the pressure goes up, the volume will go down and vice versa. However, if we put the volume inversely, then the relationship between pressure and the inversed volume will be changed into directly proportional. - KMT (Kinetic molecular theory) helps to explain macroscopic properties of gases such as pressure, temperature of volume, by considering their molecular composition and motion. It says that pressure is due to collisions between molecules moving at different velocities. If the gas is in a container, the collision with the wall is instantaneous and elastic. Therefore, its shape is changeable by pressure or temperature. However, at some point, the volume does not change little when there is no more space between molecules or the collision with wall is stronger than the pressure. As we can see in the result of the experiment, there is bigger difference between weak pressures and smaller difference between strong pressures. At the end there is almost no difference between pressures. The other graph that volume was inversely drawn shows constant increase which is directly proportion. We can also find the shape of graph from the equation. The origin equation of Boyles' law is P?1/V � P=k(1/V) � PV=k. Conclusion From the experiment, I was able to determine the mathematical relationship between pressure and volume. ...read more.

Conclusion

Moreover, I found that there was not constant pressure due to the unstable syringe, I had to make the balance point so my pressure by hands might influence the results. Improvement Fortunately, my experiment had a few odd points so it was rather successful. However, to improve my experiment, I need to figure it out the mass of the support thing that was on the top of the syringe. Due to the resistance by supporting stuff, there was not any volume difference between no book and a book. For the next time, we may find how much it can support it so we can subtract that weight. There were huge uncertainties that prove the results are not reliable. To reduce the uncertainties, we need to measure more accurately with more significant digits. Also, I can do more trials to make the result more accurately. Besides, we need to find more stable equipment that we do not need to find the balance point and put pressure by hand accidently. In addition, make it sure that the gas which was blocked to be released by piston should not be leaked. Lastly, when any scale is measured, make it sure that all of them are accurate so that the uncertainty will be less which means the experiment will be more reliable. ?? ?? ?? ?? ...read more.

This student written piece of work is one of many that can be found in our International Baccalaureate Chemistry section.

## Found what you're looking for?

- Start learning 29% faster today
- 150,000+ documents available
- Just £6.99 a month