Question

Phenol can be distinguished from ethanol by the following reagents, except:

• A. Sodium
• B. Neutral $FeCl_{3}$
• C. Phthalic anhydride/conc. $H_{2}SO_{4}$ and $NaOH$
• D. $Br _{2} / H _{2} O$

Answer 1

Answer: (A)

With neutral $FeCl_3$ solution, phenol gives violet colour solution but $6C_6H_5Oh + FeCl_3 \rightarrow \underset{\text{Violet colour compl,ex}}{[FeO(C_6H_5)_6]^{3-}} + 3H^+ + 3HCl$
Phthalic anhydride/Conc. $\text{H}_{\text{2}} \text{SO}_{\text{4}}$ and $\text{NaOH}$


Phenol cannot be distinguished from ethanol by sodium because both evolve hydrogen with sodium.
$2C_{6}H_{5}OH+2Na \rightarrow 2C_{6}H_{5}ONa+H_{2}\uparrow$
$2C_{2}H_{5}OH+2Na \rightarrow 2C_{2}H_{5}ONa+H_{2}\uparrow$