The structural formula of a benzene homologue if its molecular weight is 92.

Given:
Mr (substances) = 92

To find:
substance -?

Solution:
1) For the homologous series of benzene, there is a general formula:
CnH2n-6;
2) Make an equation and solve it to determine the structural formula of an unknown substance:
Mr (CnH2n-6) = Ar (C) * N (C) + Ar (H) * N (H);
92 = 12 * n + 1 * (2n – 6);
92 = 12n + 2n – 6
14n = 98
n = 7;
3) Unknown substance – C7H8.

Answer: Unknown substance – C7H8.