Question

If the empirical formula of a compound is CH and it has a vapour density of 13, find the molecular formula of the compound (CH = 12, H = 1)

Answer 1

Answer:

• C₂H₂

Explanation:

E.F = C.H

V.D = 13

_________

E.F w.t = CH

• 1(12) + 1(1)
• 13

_________

Mol w.t = 2(V.D)

• 2(13)
• 26

_________

n = mol.wt/emf.wt

• 26/13
• 2

_________

M.F = n(e.f)

• 2(CH)
• C₂H₂

Where:

• E.F = Empirical formula
• V.D = Vapour density
• n = Number of moles
• Mol w.t = Molecular weight
• M.F = Molecular formula

∴ C₂H₂ is the molecular formula of the compound.