Under certain conditions argon (Ar) gas diffuses at a rate of 3.2 centimeters per second. Under the same conditions, an unknown gas diffuses at a rate of 4.5 centimeters per second. What is the approximate molar mass of the unknown gas?
A.10 g/mol
B. 20 g/mol
C. 28 g/mol
D. 56 g/mol

Question

Under certain conditions argon (Ar) gas diffuses at a rate of 3.2 centimeters per second. Under the same conditions, an unknown gas diffuses at a rate of 4.5 centimeters per second. What is the approximate molar mass of the unknown gas?
A.10 g/mol
	B. 20 g/mol
	C. 28 g/mol
	D. 56 g/mol

aaronq · Answer

Graham's law

$$\frac{ rate 1 }{ rate 2 }=\sqrt{\frac{ Molarmass2 }{ Molarmass1 }}$$

notice how the placement is inversed across the equal sign