Boyle’s Law

Boyle’s Law states that the volume of a fixed mass of a gas is inversely proportional to its pressure at constant temperature.

Alternatively, Boyle’s Law states that the volume of a fixed mass of  a gas is directly proportional to the inverse of the volume , provided temperature is kept constant.

Mathematically,

 the initial pressure and volume before changes occurred.

VERIFICATION OF BOYLE’S LAW

A U-tube with an air tight is used for this experiment .

Mercury is used in the U-tube as shown in the diagram below.

when h is varies under the atmospheric pressure H , the total pressure is h+H.

Addition of mercury through H increases the height h. This  increase the pressure of h+H. The increase in pressure reduces the length of air tight column C. When the length of h reduces ,air tight column C  increases. This verifies the Boyle’s Law.

A meter rule is used to measure the length C and h . At different values of h, the respective value of C are recorded.

The graph of Pressure P=H+h  was ploted against 1/C. where Volume V = C

PRECAUTION

1. Use dry air for the experiment
2. Avoid error due to parallax
3. Take reading only when mercury level are stable

Boyle’s Law is used to determine the volume and pressure of a given mass of a gass.

Example

Calculate  the volume of  a fixed mass of a gas at pressure of 600cmHg . The pressure of the gas was 900cmHg when the volume was    30.

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