Question

how many moles does 48g of oxygen gas contain?

Answer 1

No of moles = Given mass / Molar mass

Given mass = 48g

Molar mass of $O_{2}$ = 32

No of moles = 48/32 = 3/2 = 1.5 g/mol

Answer 2

So it's oxygen gas and it contains 2 atoms of oxygen each having gram atomic mass 16 g ….so it's gram molecular mass is 32 grams

So we know that …

32 grams of oxygen gas is 1 mole

1 grams of oxygen gas is 1/32 mole

48 grams of oxygen gas is 1/32*48 mole

48 grams of oxygen gas has 1.5 moles