Question

If the number of molecules in a given sample of sulphurdioxidein 3.011*10^23.calculate:

1.the number of moles in the given sample
2.mass of sulphurdioxide in the given sample
3.no.of oxygen atoms in the given sample

Answer 1

no of molecules in sulphur dioxide

Answer 2

).6.022 x 10 23 molecules of SO 2 = 1 mole of SO2

So, 3.011 x 10 23 molecules of SO 2 = (1/6.022 x 10 23 ) x 3.011 x 10 23 mole of SO2 = 0.5 moles of  SO2

b). 1 mole of SO2 = 32 + 2 x 16 = 64 gm

So, 0.5 mole of sample of ​ SO2 = 64 x 0.5 = 32 gm

c). Mass of oxygen in  64 gm = (32 / 64)  x100 = 50 %

hence, mass of oxygen atoms in given sample (32 gm) = 32 x 50/100 = 16 gm