What is the mass in grams of 57 x 1019 CH4 moleculesSolution

What is the mass in grams of 5.7 x 10¹⁹ CH4 molecules?

number of CH4 molecules = 5.7x10^19

molar mass of CH4= 16.04 gram/mole

mass of 1 mole of CH4= 16.04 grams

1 mole of CH4 contains Avagadro number of CH4 molecules

Avagadro number = 6.023x10^23

mass of 6.023x10^23 molecules of CH4= 16.04 grams

mass of 5.7x10^19 molecules of CH4 = ?

= 16.04 x5.7x10^19/6.023x10^23

= 15.18x10^-4

mass of CH4 = 15.18x10^-4 grams= 0.001518 grams