Question

calculate the number of moles present in 56 gram of Nitrogen gas

Answer 1

mole = given mass \ molar mass
mole=56\14
mole=4

Answer 2

Atomic mass of N2 is 14 g

Therefore , 14 g of N2 = 1 mole
56 g of N2 = x

14 g x = 56 g
x = 56/14 = 4 mole