Question

A dibasic acid (A) with a dipole moment (non-zero) de-colourises bromine water. Functional isomer of A is an ester B. A & B are respectively:

• A.
• B.
• C.
• D. A is HOOC - CH = CH - COOH but there is no possible structure for B

Answer 1

The correct option is B

A is dibasic
It also decolorizes $B{r}_2$ water
$\Rightarrow$ it has C = C or C $\equiv$ C
Also A has non-zero depole moment
$\Rightarrow$ A is of cis form as trans isomer will not have a non-zero dipolem
An ester should have $O\parallel -C-O-C$ in its structure
In option (a) A has trans structure
In option (b) A has the required structure
Also B is of the ester form
Ans (b)
Note : Both A and B should have the same molecular formula In C, the structure of B