1. BOYLE’S LAW

2. OBJECTIVE: To determine the relationship between pressure and volume by performing Boyle’s Law experiment.

3. THEORY: BOYLE’S LAW If pressure, volume or temperature remains constant, the other two cannot be varied independently of each other. At a constant temperature, Boyle Law states P V = const. Boyles law may be proved by a gas thermometer.

4. The gas thermometer has a hand pump to generate pressure at the open end of the tube. P = h Hg * ρ Hg * g h Hg = Height of mercury seal ρ Hg = Density of mercury = 13.6 g cm -3 g = 9.8 m/s 2 = acceleration of free fall Volume of enclosed air in the column V = ∏ * d 2 * h 4 d = 2.7 mm = Inside diameter of the capillary

5. HOW TO CALCULATE THE PRESSURE P Hg = h Hg * ρ Hg * g = 13.6 gcm -3 * 9.8 m/s 2 * 11mm = 15 Pa The pressure P may now be calculated by P = P 0 + P Hg + ∆P Then, it may be represented as a function of V Where, V= ∏ * d 2 * h 4

6. TOOLS : Gas thermometer Graphing paper Pencil Pen Eraser Calculator Ruler

8. STEPS: 1.Read height h Hg from the scale of gas thermometer. 2.Generate pressure with hand pump, increasing it step by step. 3.Read height ‘h’ of the air column each time and record it.

9. DATA: Outside pressure = P 0 = 1011 hPa Height of mercury seal = h Hg = 11mm TABLE 1 Height of the enclosed quantity of air as a function of pressure. ∆P (hPa)h (cm)h (mm) 0 -10 -20 -30 -40

10. P = P 0 + P Hg +∆P Where: P = Pressure P 0 = Atmospheric Pressure (1011 hPa) P Hg = Pressure of Mercury in a gas thermometer (15 hPa) ∆P = Change of pressure V= π d 2 × h 4 Where: V = Volume π = 3.14 d = diameter (2.7 mm) h = height of Mercury column

11. V (mm 3 )P (hPa) TABLE 2 From Table 2 the chart may be drawn.