Question

The molecule’s mass of oxygen is 32. 

a. What is the GMM of O₂ 

b. How many moles of molecules are there in 64g of oxygen? How many molecules are there in it? 

c. Calculate the number of oxygen atoms present in 64g of oxygen?

Answer 1

a. GMM of O₂  = 2 × 16 = 32 g

b. No. of mole molecules = \(\frac{Mass}{GMM}\) = \(\frac{64}{32}\) = 2

Number of molecules = mole × 6.022 × 10²³

= 2 × 6.022 × 10²³ 

c. Number of atoms = Number of molecules × number of atoms in one molecules Number of atoms in one molecules of oxygen (O₂) =2 

∴ total number of atoms = 2 × 6.022 × 10²³

= 4 x  6.022 × 10²³