Physics Ib

IB Physics SL

Investigating Boyle’s Law

Introduction

The aim of this experiment is to find out whether or not Boyle’s law is obeyed when a volume of fixed mass of gas is compressed using a pressure gauge at constant room temperature. Boyle’s law states that for a fixed mass of gas at constant temperature, the pressure of gas is inversely proportional to its volume.

P∝1V

P= pressure (Pa) and V= volume (cm⁻3)

Methodology

To achieve the aim, I will need to use the following apparatus: a pump, a pressure gauge, a graduated glass tube, oil, a fixed mass of gas, a computer, graph paper and a calculator.

Diagram:

Glass tube

From pump

Oil

Volume of fixed mass of gas

Pressure gauge

Computer

Calculator

Glass tube

From pump

Oil

Volume of fixed mass of gas

Pressure gauge

Computer

Calculator

1. Set up the above apparatus using a volume of fixed mass of gas

2. Connect the pump to the pressure gauge and pump it until the pressure is at 2.4 x 10⁵ Pa

3. Slowly reduce the pressure by releasing air carefully, by intervals of 0.1 and at times 0.2 x 10⁵ Pa and notice how the volume of gas inside the graduated glass tube changes

4. Continue until maximum pressure of 0.9 x 10⁵ Pa is reached and record all readings

5. Take a series of readings of pressure and volume and display them in a table of results

6. Repeat the experiment and take an average of the results

Results table

Errors

Pressure error: half a division → 0.05 Pa

Volume error: half a division → 0.5 cm

2. 33 ± 1.0 cm⁻3

Error V: 1/33 x 100 = 3.03%

Error 1/V: 1/33 = 0.030

3.03% of 0.030

3.03/100 x 0.030 = 0.0009

Absolute Error: 0.030 ± 0.0009 cm⁻3

2. 33 ± 1.0 cm⁻3

Error V: 1/33 x 100 = 3.03%

Error 1/V: 1/33 = 0.030

3.03% of 0.030

3.03/100 x 0.030 = 0.0009

Absolute Error: 0.030 ± 0.0009 cm⁻3

1 . 31 ± 1.0 cm⁻3

Error V: 1/31 x 100 = 3.23%

Error 1/V: 1/31 = 0.032...