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Question
If sulphur exists as S8 molecules, calculate the number of moles in 100 g of sulphur. (S = 32 u)
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Solution
Mass of sulphur = 100g (sulphur exists as S8 molecules)
molecular mass of sulphur = (8 × 32) = 256g
Number of moles in 256g of sulphur = 1 mole
Therefore, number of moles in 100g of sulphur = 100/256 = 0.39 moles
Hence, 100g of sulphur contains 0.39 moles of sulphur.
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