Question

calculate the mass of 3.011×10^23 molecules of nitrogen gas

Answer 1

given,
molar mass of N2 gas = 28 g/mol.
mass = ?
no. of molecules = 3.011 x 10^23
avogadro's no. = 6.022 x 10^23
since,
mole = mass / molar mass .........(1)
and
mole = no. of molecules / avogadro's no .......(2)
from (1) and (2),
mass / molar mass = no of molecules / avogadro's no
mass / 28 = 3.011 x 10^23 / 6.022 x 10^23
mass / 28 = 1/2
mass = 14 g