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Question
If the empirical formula of a compound is CH and it has a vapor density of 13, find the molecular formula of the compound.
Solution
Given:
Empirical formula = CH
Vapour density = 13
Molecular weight = 2 × Vapour density
= 2 × 13
= 26
∴ Empirical formula of a compound with molecular mass 26 is CH.
`n = "Molecular mass"/"Empirical formula" = 26/(12+1) = 26/13 = 2`
∴ Molecular formula of the given compound is 2 × (CH) = C2H2 = CH ≡ CH.
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