At a given temperature, an unknown gas takes 10.0 minutes to travel the distance helium gas travels in 1.66 minutes. What is the approximate molar mass of the unknown gas

The molar mass of the unknown is approximate 145g/mol

Explanation:

We can relate the speed of effusion of gases with the molar mass of the 2 compounds using Graham´s law:

Where V is speed of the gas and m molar mass of a and b gases.

Molar mass of helium is 4g/mol. As the distance of the gases is the same, we can replace the speed of effusion with the time the gas takes to travel the distance. The equation will be:

Replacing:

i just got this problem. it's 90.3

the answer would be c