Boyle's Law or Mariotte's Law or Boyle-Mariotte Law

Boyle's Law

Boyle's Law states that " At a constant Temperature, the Volume of a confined gas ( gas restricted to certain limits,for eg., gas in a closed system ) is INVERSELY proportional to the Pressure to which it is subjected ".

The Law was named after a Chemist and Physicist Robert Boyle , who published the Law in 1662.

Robert Boyle studied the Compressibility of Gases in 1660. In his Experiments he observed that "At a fixed Temperature, the Volume of a gas is inversely proportional to the Pressure exerted by the gas."

For Eg :- If the Volume is Halved, the Pressure is Doubled and if the Volume is Doubled, the Pressure is Halved. The reason for this effect is that a Gas is made up of loosely spaced molecules moving randomly. Thus if a gas is Compressed in a vessel, the molecules are pushed together and the gas occupies less Volume. Due to this the molecules having less space to move, hit the walls of the vessel thus exerting an increased Pressure.

Mathematically the Law can be stated as :-

Pressure x Volume = Constant or

PV = k .

The value of the constant k depends on the units used for the other quantities,but once the units are fixed, k is also fixed.

When any one of the quantities V, P, or T are changed, one or two of the others must change so that the equation above still remains true.

A French Physicist Edme Mariotte discovered the same law independently of Boyle in 1676, and hence sometimes Boyle's Law is also referred to as Mariotte's or the Boyle-Mariotte law.