NEET · Chemistry · STD 12 - 7. Alcohol, phenol and ethers
The functional group that can be identified through phthalein dye test is :
- A Aldehyde
- B Phenolic
- C Carboxylic acid
- D Alcohol
Answer & Solution
Correct Answer
(B) Phenolic
Step-by-step Solution
Detailed explanation
(B) Phenolic
The phthalein dye test is a characteristic test used for the identification of the phenolic functional group.
When a phenol is heated with phthalic anhydride in the presence of concentrated sulfuric acid, it undergoes a condensation reaction to form a colorless compound, phenolphthalein.
Upon adding an alkaline solution like dilute sodium hydroxide (NaOH) to this mixture, a characteristic pink or red color is produced due to the formation of the phenolphthalein anion.
Therefore, the functional group identified through the phthalein dye test is phenolic.
The phthalein dye test is a characteristic test used for the identification of the phenolic functional group.
When a phenol is heated with phthalic anhydride in the presence of concentrated sulfuric acid, it undergoes a condensation reaction to form a colorless compound, phenolphthalein.
Upon adding an alkaline solution like dilute sodium hydroxide (NaOH) to this mixture, a characteristic pink or red color is produced due to the formation of the phenolphthalein anion.
Therefore, the functional group identified through the phthalein dye test is phenolic.
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