An effusion experiment requires `40 s` of a certain number of moles of a gas of unknown molar mass to pass through a small orifice into a vaccum. Under the same conditions, `16 s` was required for the same number of moles of `O_(2)` to effuse. What is the molar mass of the unknown gas?

In a mixture of O_(2) and an unknown gas, the percentage of the unknown gas is 20% by mass. At a given temperature and pressure, time required to effuse V mL of the gas mixture through an aperrture is 234.1 s. under the same conditions, time required to effuse the same volume of pure O_(2) gas is 223.1 s. what is the molar mass of unknown gas?

The rate of effusion of an unknown gas (X) through a pinhole is found to be 0.279 times the rate of effusion of hydrogen gas through the same pinhole, if both are at STP. What is the molecular mass of the unknwon gas ?

It takes 192 sec for an unknown gas to diffuse through a porous wall and 84 sec for N_(2) gas to efffuse at the same temperature and pressure. What is the molar mass of the unknown gas?

A certain volume of argon gas (Mol. Wt.=40) requires 45s to effuse through a hole at a certain pressure and temperature. The same volume of another gas of unknown molecular weight requires 60s to pass through the same hole under the same conditions of temperature and pressure. The molecular weight of the gas is:

Some moles of O_(2) diffuse through a small opening in 18 second. Same number of moles of an unknown gas diffuse through the same opening in 45 second. Molecular mass of the unknown gas is