Chat with tutor

Ask Questions, Get Answers


How to distinguish between (i) Phenol and alcohol (ii) Prima

How to distinguish between (i) Phenol and alcohol (ii) Primary, secondary and tertiary alcohol

1 Answer


(i)Phenol on reaction with neutral FeCl3 gives purple colour whereas alcohols do not give purple colour.

$6C_6H_5OH + Fe^{3+} \to [Fe(OC_6H_5)_6]^{ 3-} + 6^{ H+}$ Purple colour

(ii) Primary, secondary and tertiary alcohol:

 Lucas reagent test:

$ROH + HCl \longrightarrow{

conc.HCl ZnCl2} RCl + H_2O $

If it is a primary alcohol, no turbidity appears at room temperature.

Turbidity appears only on heating. 

If it is a secondary alcohol, turbidity appears in 5 minutes. 

If it is a tertiary alcohol, turbidity appears immediately.

(iii)Methanol and ethanol:

 Iodoform test:

Ethanol when reacted with (I2 and NaOH) or NaOI gives yellow ppt of iodoform since it has the presence of $CH_3-CH (OH)-$ group.

$ C_2H_5OH +4I_2+ 6NaOH \to CHI_3 + 5NaI + 5H_2O + HCOONa$ Yellow ppt. $CH3OH + I_2+ NaOH \to$ NO YELLOW PPT

Help Clay6 to be free
Clay6 needs your help to survive. We have roughly 7 lakh students visiting us monthly. We want to keep our services free and improve with prompt help and advanced solutions by adding more teachers and infrastructure.

A small donation from you will help us reach that goal faster. Talk to your parents, teachers and school and spread the word about clay6. You can pay online or send a cheque.

Thanks for your support.
Please choose your payment mode to continue
Home Ask Homework Questions
Your payment for is successful.
Clay6 tutors use Telegram* chat app to help students with their questions and doubts.
Do you have the Telegram chat app installed?
Already installed Install now
*Telegram is a chat app like WhatsApp / Facebook Messenger / Skype.