Question

The molecular mass of a compound with empirical formula ch is 78. Find its molecular formula

Answer 1

Molecular mass of a compound with empirical formula CH is 78.

we know, molecular mass = n × empirical mass

⇒ 78 = n × (mass of CH )

⇒ 78 = n × (12 + 1)

⇒78 = n × 13

⇒n = 6

so, molecular formula = n × empirical formula

= 6 × (CH)

= C6H6

hence, compound chemical formula/molecular formula is C6H6. i.e., compound is not other than benzene.