The molecular formula of sulphur is given to be S₈. It contains 8 atoms of sulphur.

The molecular mass of sulphur molecule = 32 x 8 = 256u.

Therefore, 1 mole of sulphur molecules = 256 g

Now, 256g of sulphur = 1 mole of sulphur molecules

Hence, 16g of sulphur = 16/256 mole of sulphur molecules = 0.0625 moles of Sulphur molecules

Also, 1 mole of sulphur molecules = 6.023 x 10²³ molecules

0.0625 mole of sulphur molecules = 6.023 x 10²³ x 0.0625 molecules = 3.76 x 10²² molecules

Therefore, the number of molecules present in 16 g sulphur is 3.76 x 10²²