Question

The molar mass of an unknown gas was measured by an effusion experiment. It was found that it took 63 s for the gas to effuse, whereas nitrogen gas (N2) required 48 s. The molar mass of the unknown gas is-

Answer 1

Answer:

8.13 g/mol.

Explanation:

The following formula gives us the relationship between the effusion rates of two gases and their molar masses:

$\sqrt{\frac{MM_{x} }{MM_{y} } } = \frac{rate_{y} }{rate_{x} }$

where x and y are respective sample gases and MM and rate are molar mass and rate of effusion respectively.

⇒$\sqrt{\frac{14}{y} } = \frac{63}{48}$

$\frac{14}{y} = 1.3125^{2}$

y= 14 / $1.3125^{2}$  = 8.13 g/mol.