Alcohols, Phenols and Ethers

NEET Chemistry · 67 questions · Page 2 of 7 · Click an option or "Show Solution" to reveal answer

Q11

The reaction, is called

A Etard reaction

B Gattermann-Koch reaction

C Williamson synthesis

D Williamson continuous etherification process

Correct Answer

Option C

Solution

Williamson synthesis is the best method for the preparation of ethers.

Q12

Among the following sets of reactants which one produces anisole?

A CH 3 CHO ; RMgX

B C 6 H 5 OH ; NaOH ; CH 3 I

C C 6 H 5 OH ; neutral FeCl 3

D C 6 H 5 CH 3 ; CH 3 COCl ; AlCl 3

Correct Answer

Option B

Solution

Phenols react with alkyl halides in alkaline medium to form ethers. Therefore,

Q13

Which of the following will not be soluble in sodium hydrogen carbonate?

A 2, 4, 6 - Trinitrophenol

B Benzoic acid

C o-Nitrophenol

D Benzenesulphonic acid

Correct Answer

Option C

Solution

Acid reacts with sodium hydrogen carbonate as follows : Among all the given options ortho-nitrophenol is weaker acid than HCO 3 hence, it does not react with NaHCO 3 .

Q14

Number of isomeric alcohols of molecular formula C 6 H 14 O which give positive iodoform test is

A three

B four

C five

D two

Correct Answer

Option B

Solution

The iodoform test is positive for alcohols with formula R — CHOH — CH 3 .

Among C 6 H 14 O isomers, the ones with positive iodoform test are:

Q15

Which of the following compounds can be used as antifreeze in automobile radiators?

A Methyl alcohol

B Glycol

C Nitrophenol

D Ethyl alcohol

Correct Answer

Option B

Solution

Glycol is used as an antifreeze in automobiles.

Q16

When glycerol is treated with excess of HI, it produces

A 2-iodopropane

B allyl iodide

C propene

D glycerol triiodide

Correct Answer

Option A

Solution

Glycerol when treated with excess HI produces 2–iodopropane.

Q17

Following compounds are given Which of the above compound(s), on being warmed with iodine solution and NaOH, will give iodoform?

A (i), (iii) and (iv)

B Only (ii)

C (i), (ii) and (iii)

D (i) and (ii)

Correct Answer

Option C

Solution

The iodoform test is exhibited by ethyl alcohol, acetaldehyde, acetone, methyl ketones, those alcohols which possess CH 3 CH(OH)— group, acetophenone, $\alpha$ -hydroxypropionic acid, keto acid, 2-aminoalkanes, etc.

Q18

Among the following four compounds (i) Phenol (ii) Methyl phenol (iii) Meta -nitrophenol (iv) Para -nitrophenol The acidity order is

A (iv) > (iii) > (i) > (ii)

B (iii) > (iv) > (i) > (ii)

C (i) > (iv) > (iii) > (ii)

D (ii) > (i) > (iii) > (iv)

Correct Answer

Option A

Solution

In phenols, the presence of electron releasing groups decrease the acidity, whereas presence of electron withdrawing groups increase the acidity, compared to phenol.

Among the meta and para-nitrophenols, the latter is more acidic as the presence of –NO 2 group at para position stabilises the phenoxide ion to a greater extent than when it is present at meta position.

Thus, correct order of acidity is : (iv) > (iii) > (i) > (ii)

Q19

Given are cyclohexanol (I), acetic acid (II), 2, 4, 6-trinitrophenol (III) and phenol (IV). In these the order of decreasing acidic character will be

A III > II > IV > I

B II > III > I > IV

C II > III > IV > I

D III > IV > II > I

Correct Answer

Option A

Solution

As we know that phenols and carboxylic acids are more acidic than aliphatic alcohols thus cyclohexanol is least acidic.

On the other hand III is more acidic than IV because of the presence of three highly electron with drawing NO 2 groups on the benzene ring which makes the OH bond extremely polarized.

This facilitates the release of H + .

In acetic acid the electron withdrawing

- \mathop C\limits_| = O

group polarizes the O-H bond and increases the acid strength.

Thus, acetic acid is more acidic than phenol or cyclohexanol.

Thus, the order of acidic strength will be III > II > IV > I

Q20

The general molecular formula, which represents the homologous series of alkanols is

A C n H 2n O

B C n H 2n O 2

C C n H 2n + 2 O

D C n H 2n + 1 O

Correct Answer

Option C

Solution

All alcohols follow the general formula as C n H 2n+2 O.

Ready for a full NEET mock test? Timed · full syllabus · instant results

Take a Mock Test →