NEET Chemistry Alcohols,Phenols and Ethers Questions Solved

Which of the following will not form a yellow precipitate on heating with an alkaline solution of iodine?

(a) CH₃CH(OH)CH₃ (b) CH₃CH₂CH(OH)CH₃

#Alcohols: Preparation, Physical and Chemical Properties

CH₃CO- group directly or it $H {CH}_{3} - C_{|}^{|} - OH$ has group.

(a) CH₃CH(OH)CH₃ + I₂ $\overset{NaOH}{\to}$ CH₃COCH₃ + 2HI + 3NaI + CH₃COONa + 3H₂O

CH₃COCH₃ + 3I₂ + 4NaOH $\to$ CHI₃ $↓$ + 3NaI + CH₃COONa + 3H₂O

yellow ppt.

(b) CH₂-CH₂CH(OH)CH₃ + I₂ $\to$ + 2HI

It gives iodoform test

It does not have methyl ketone group, so it does not give yellow ppt with I₂ in presence of alkali.

(d) CH₃CH₂OH + I₂ $\to$ ${CH}_{3} - \underset{| |}{C} - H O$ + 2HI

It gives iodoform test

presence of -COCH₃, it gives Haloform reaction.

Difficulty Level:

(a)
10%
(b)
15%
(c)
62%
(d)
15%

n-propyl alcohol and iso-propyl alcohol can be chemically distinguished by which reagent

(a) ${PCl}_{5}$

(b) reduction

(d) ozonolysis

#Alcohols: Preparation, Physical and Chemical Properties

${CH}_{3} - {CH}_{2} - {CH}_{2} OH \to_{K_{2} {Cr}_{2} O_{7} / H_{2} {SO}_{4}}^{[O]}$ ${CH}_{3} - {CH}_{2} - CHO$

n-propyl alcohol Propionaldehyde

$1^{°}$ alcohol

$\to_{K_{2} {Cr}_{2} O_{7} / H_{2} {SO}_{4}}^{[O]}$

Iso-propyl alcohol Acetone

$2^{°}$ alcohol

Difficulty Level:

(a)
20%
(b)
17%
(c)
54%
(d)
11%

Among the following sets of reactants which one produces anisole?

(a) CH₃CHO, RMgX

(b) C₆H₅OH, NaOH, CH₃I

(d) C₆H₅-CH₃, CH₃COCl, AlCl₃

#Ethers: Preparation, Physical & Chemical Properties, Uses

(b) Williamson's synthesis

Difficulty Level:

(a)
13%
(b)
50%
(c)
14%
(d)
24%

Consider the following reaction,

Ethanol $\overset{{PBr}_{3}}{\to}$ X $\overset{Al . KOH}{\to}$ Y $\to_{(ii) H_{2} O, heat}^{(i) H_{2} {SO}_{4}, room temperature}$ Z

The product Z is

(a) CH₂=CH₂

(b) CH₃CH₂OCH₂CH₃

(d) CH₃CH₂OH

#Alcohols: Preparation, Physical and Chemical Properties

(d)

Difficulty Level:

(a)
20%
(b)
19%
(c)
19%
(d)
45%

In the following sequence of reactions,

${CH}_{3} - Br \overset{KCN}{\to}$ A $\overset{H_{3} O^{+}}{\to}$ B $\to_{ether}^{{LiAlH}_{4}}$ C

the end product C is

(a) acetone (b) methane

#Alcohols: Preparation, Physical and Chemical Properties

(d) ${CH}_{3} Br \to_{- KBr}^{KCN} Methyl bromide$ ${CH}_{3} CN \overset{H_{3} O^{+}}{\to} Ethane nitrite A$ ${CH}_{3} COOH \to_{Ether}^{{LiAlH}_{4}} Ethanoic acid B$ ${CH}_{3} {CH}_{2} OH Ethanol C$

In the presence of ${LiAlH}_{4}$ carboxylic acid reduce in alcohols, directly.

Difficulty Level:

(a)
8%
(b)
13%
(c)
26%
(d)
55%

Which one is formed when sodium phenoxide is heated with ethyl iodide?

(a) Phenetole

(b) Ethyl phenyl alcohol

(d) None of the above

#Ethers: Preparation, Physical & Chemical Properties, Uses

(a) When sodium phenoxide (C₆H₅ONa) is heated with ethyl iodide (C₂H₅I) it forms ethyl phenyl ether which is also called phenetole. This reaction is called Williamson's synthesis.