Question

Find the molecular formula of the compound with molar mass 78 g mol and empirical formula CH.
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Answer 1

Answer:

The molecular formula is C₆H₆

Explanation:

The empirical formula = CH

Let the molecular formula of the compound be (CH)n

The molecular mass of carbon = 12g

The molecular mass of hydrogen = 1g

Hence the molecular mass of CH = 12 + 1 = 13g

∴ The molecular mass of the compound is 13×n

The molecular mass of the compound is 78g.

∴ 13×n = 78 → n = 78÷13 = 6

→ The molecular formula is (CH)₆ = C₆H₆