Boyle's law of the gas, and "k" is a constant. The equation states that the product of pressure and volume is a constant for a given mass of confined gas and this holds as long as the temperature is constant. For comparing the same substance under two different sets of conditions, the law can be usefully expressed as The equation shows that, as volume increases, the pressure of the gas decreases in proportion. Similarly, as volume decreases, the pressure of the gas increases. The law was named after chemist and physicist Robert Boyle, who published the original law in 1662. This relationship
Thomas Graham (chemist) is known for his studies on the behaviour of gases, which resulted in his formulation of two relationships, both since becoming known as "Graham's Laws," the first regarding gas diffusion, and the second regarding gas effusion. In the former case, Graham deduced that when measured repeatedly under the same conditions of pressure and temperature, the rate of diffusive mixing of a gas is inversely proportional to the square root of its density, and given the relationship between density and molar mass, also inversely proportional to the square root of its molar mass. In the same way, in the latter case,