# Graham's Law

Written by Jerry Ratzlaff. Posted in Properties

Graham's Law also known as Graham's Law of Effusion is the rate at which gases disperse is inversely proportional to the square root of their mass. Or you could say the process in which one gas scatters itself within another.

## formula

$$\frac {R_1} {R_2} = \sqrt { \frac { M_2 } { M_1 } }$$

Where:

$$R_1$$ = the rate of effusion of the first gas (volume or number of moles per unit time)

$$R_2$$ = the rate of effusion for the second gas

$$M_1$$ = molar mass of gas one

$$M_2$$ = molar mass of gas two