Question

 An organic compound containing C, H and O exists in two isomeric forms, A and B. An amount of 0.108 g of one of the isomers gives on combustion 0.308 g of CO₂ and 0.072 g of H₂O. A is insoluble in NaOH. A reacts with conc. HI to give compounds C and D. C can be separated from D by the ethanolic AgNO₃ solution and D is soluble in NaOH. B reacts readily with bromine water to give compound E of molecular formula, C₇H₅OBr₃. Identify A, B, C, D and E with justification and give their structures.

Answer 1

(i) For empirical formula of (A):

 Empirical formula of A = C₇H₈O

(ii) Since B gives C₇H₅OBr₃ and B is isomer to A . thus, molecular formula of A and B is C₇H₈O.

(iii) A is insoluble in NaOH and NaHCO₃, so A is

(iv) A is also confirmed by action with HI

B is soluble in NaOH and gives E (C₇H₅OBr₃) with Br₂ water and so B is

2.4.6,- tribromo m- cresol

meta-position can provide tribromo derivative.