Calculate the number of SO2 molecules in 32 g SO2

Question

 Calculate number of molecules

Answer 1

Divide the given mass by the molecular weight of SO₂ to get number of moles (n), then multiply moles by Avogadro's number to get number of molecules (N).

 

Atomic weights:

 

S = 32.07 g/mole

O = 16.00 g/mole

 

Molecular weight:

 

SO₂ = 32.07 + 2(16.00) = 64.07 g/mole 

 

n = (32 g) / (64.07 g/mole) = 0.49945 moles

 

N = nA = (0.49945 moles) (6.02 x 10²³ molecules/mole) = 3.007 x 10²³ molecules

 

There are about 3.007 x 10²³ molecules of SO₂ in 32 g of SO₂.