Question

Given the mass of a particular gas and the molar mass of the atoms or molecules in the gas, how do you find the number of moles?

Divide the molar mass by the mass of the gas.

OR

Multiply the mass of the gas by the molar mass.

OR

Divide the mass of the gas by the molar mass.

Answer 1

molar mass=mass of a mole of atoms or molecules

hence if there are N moles of atoms/molecules,

total mass=N*molar mass

hence N can be found out by

N=total mass/molar mass

so option 3 is correct.

Divide the mass of the gas by the molar mass.