How many molecules of Na2O are in 24.6g? Show work!

Explanation:

Na2O has 2 atoms of Sodium and 1 atom of Oxygen

So, the molecular mass of Na2O is:

(2 x Atomic weight of Na) + (1 x Atomic weight of O)

Atomic weight of Na = 22.99 g

Atomic weight of O = 16 g

Therefore, Molecular Mass of Na2O = (2x 22.99g) + (1 x 16g)

= (45.98 + 16)g = 61.98 g

Therefore 61.98 g of Na2O contains 6 x 10^23 molecules (Avogadro's number).

24.6 g of Na2O therefore contains:

(24.6/61.98) x 6 x 10^23 = Answer!