Question

Distinction between two functional isomers of the same main functional group can be made by :

• A. iodoform test
• B. tollen's test
• C. $B{r}_2$ water
• D. phthalein test

Answer 1

Answer: (A), (B)

iodoform test
tollen's test

A) The iodoform test or iodoform reaction is a qualitative chemical test for the detection of ketones and aldehydes carrying an alpha methyl group. The reagents are iodine and sodium hydroxide.
B) Tollens test, also known as silver-mirror test, is a qualitative laboratory test used to distinguish between an aldehydes and a ketones. It exploits the fact that aldehydes are readily oxidized, whereas ketones are not. Tollens test uses a reagent known as Tollens reagent, which is a colorless, basic, aqueous solution containing silver ions coordinated to ammonia $\left[Ag\right(NH3{)}^{2+}]$.
C) The bromine test is a qualitative test for the presence of unsaturation (carbon to carbon double or triple bonds) and Phenols.
D) Phthalein test is used to identify the phenols only.
Aldehydes will have double bond and alcohols will have single bond. Hence, options A & B are correct.