An unknown compound of carbon, hydrogen and oxygen contains 69.77 % C and 11.63 % H and has a molecular weight of 86. It does not reduces Fehling's solution but forms a bisulphate addition compound and gives a positive iodoform test. What is the possible structure(s) of unknown compound?

Question

An unknown compound of carbon, hydrogen and oxygen contains 69.77 % C and 11.63 % H and has a molecular weight of 86. It does not reduces Fehling's solution but forms a bisulphate addition compound and gives a positive iodoform test. What is the possible structure(s) of unknown compound? (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

From the given elemental composition, empirical formula can be derived as :

Element	C	H	O
Weight %	69.77	11.63	18.60
Mole %	5.81	11.63	$1.1625$ (obtained by dividing from $M$ )
Simple ratio	5	10	1

Hence, empirical formula is

C_{5} H_{10} O

and empirical formula
weight is

86

.
Since, empirical formula weight and molecular weight both are

(86)

, empirical formula is the molecular formula also.
Also, the compound does not reduce Fehling's solution, therefore it is not an aldehyde, but it forms bisulphite, it must be a ketone.
Also, it gives positive iodofonn test, it must be a methyl ketone.

C_{3} H_{7} - C ∣∣ O - C H_{3}

Based on the above information, the compound may be one of the following :

Q. An unknown compound of carbon, hydrogen and oxygen contains 69.77%C and 11.63%H and has a molecular weight of 86. It does not reduces Fehling's solution but forms a bisulphate addition compound and gives a positive iodoform test. What is the possible structure(s) of unknown compound?

Q. An unknown compound of carbon, hydrogen and oxygen contains $69.77% C$ and $11.63% H$ and has a molecular weight of $86$ . It does not reduces Fehling's solution but forms a bisulphate addition compound and gives a positive iodoform test. What is the possible structure(s) of unknown compound?