An organic compound (A) (mol. Wt. =74) contained C(48.65%), H(8.11%) and O(43.24%). (A) on treatment with bromine, gave (B) containing 52.3% of Br, while on treatment with phosphorus and bromine, gave (C ) containing 74.1% of bromine. Both (B) and (C ), on boiling with water, gave the same product (D). (A), on distillation with soda lime, gave ethane. Assign structural formulae to (A), (B), (C ) and (D)

An organic compound (A) (mol. Wt. =74) contained C(48.65%), H(8.11%) a

1.	An organic compound (A) (mol. Wt. =74) contained C(48.65%), H(8.11%) and O(43.24%). (A) on treatment with bromine, gave (B) containing 52.3% of Br, while on treatment with phosphorus and bromine, gave (C ) containing 74.1% of bromine. Both (B) and (C ), on boiling with water, gave the same product (D). (A), on distillation with soda lime, gave ethane. Assign structural formulae to (A), (B), (C ) and (D)
Answer» Solution :For the compound (A) Moles of `C:H:O= (48.65)/(12): (8.11)/(1): (43.24)/(16)` `=4.054: 8.11: 2.70` `=1.5: 3: 1` `=3: 6: 2` `therefore` empirical formula of (A) is `C_(3)H_(6)O_(2)` (74) As the mol. Wt. = emp. Formula wt, `therefore` molecular formula of (A) is `C_(3)H_(6)O_(2)` As (A), on DISTILLATION with soda LIME gave `C_(2)H_(6)`, (A) must be `CH_(3).CH_(2).COOH` (propioic acid) Now For (B): Br% `=(80)/(153) XX 100 ~~52.3%` For (C ): `Br%= (160)/(216)xx 100~~74.1%` As the Br% in (B) and (C ) are same as given (B) is `CH_(3).CHBr.COOH` and (C ) is `CH_(3).CHB.CO.Br` Now since both (B) and (C ) will give the same PRODUCT `CH_(3).CH(OH).COOH` (`alpha`-hydroxy propionic acid), (D) must be `CH_(3).CH(OH).COOH`