CBSE Class 12 Chemistry HOTs Alcohols Phenols And Ethers

Question. The general molecular formula, which represents the homologous series of alkanols is
(a) C_nH_2n+2O
(b) C_nH_2nO₂
(c) C_nH_2nO
(d) C_nH_{2n + 1}O 
Answer: A

Question. Reaction between acetone and methyl magnesium chloride followed by hydrolysis will give
(a) iso-propyl alcohol
(b) sec-butyl alcohol
(c) tert-butyl alcohol
(d) iso-butyl alcohol.
Answer: C

Question. When vapours of a secondary alcohol is passed over heated copper at 573 K, the product formed is
(a) a carboxylic acid
(b) an aldehyde
(c) a ketone
(d) an alkene.
Answer: C

Question. Reaction of phenol with chloroform in presence of dilute sodium hydroxide finally introduces which one of the following functional group?
(a) –COOH
(b) –CHCl₂
(c) –CHO
(d) –CH₂Cl
Answer: C

Question. 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 
Answer: C

Question. Number of isomeric alcohols of molecular formula C₆H₁₄O which give positive iodoform test is
(a) three
(b) four
(c) five
(d) two.
Answer: B

Question. 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
Answer: A

Question. 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)
Answer: A

Question. When glycerol is treated with excess of HI, it produces
(a) 2-iodopropane
(b) allyl iodide
(c) propene
(d) glycerol triiodide
Answer: A

Question. Ethylene oxide when treated with Grignard reagent yields
(a) primary alcohol
(b) secondary alcohol
(c) tertiary alcohol
(d) cyclopropyl alcohol
Answer: A

Question. Which one 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
(c) CH₃OH
(d) CH₃CH₂OH
Answer: C

Question. n-Propyl alcohol and isopropyl alcohol can be chemically distinguished by which reagent?
(a) PCl₅
(b) Reduction
(c) Oxidation with potassium dichromate
(d) Ozonolysis 
Answer: C

Question. When phenol is treated with CHCl₃ and NaOH, the product formed is
(a) benzaldehyde
(b) salicylaldehyde
(c) salicylic acid
(d) benzoic acid. 
Answer: B

Question. Which of the following is correct?
(a) On reduction, any aldehyde gives secondary alcohol.
(b) Reaction of vegetable oil with H₂SO₄ gives glycerine.
(c) Alcoholic iodine with NaOH gives iodoform.
(d) Sucrose on reaction with NaCl gives invert sugar.
Answer: C

Question. When 3,3-dimethyl-2-butanol is heated with H₂SO₄, the major product obtained is
(a) 2,3-dimethyl-2-butene
(b) cis and trans isomers of 2,3-dimethyl-2-butene
(c) 2,3-dimethyl-1-butene
(d) 3,3-dimethyl-1-butene.
Answer: A

Question. On heating glycerol with conc. H₂SO₄, a compound is obtained which has bad odour. The compound is
(a) acrolein
(b) formic acid
(c) allyl alcohol
(d) glycerol sulphate.
Answer: A

Question. Ethanol and dimethyl ether form a pair of functional isomers. The boiling point of ethanol is higher than that of dimethyl ether, due to the presence of
(a) H-bonding in ethanol
(b) H-bonding in dimethyl ether
(c) CH₃ group in ethanol
(d) CH₃ group in dimethyl ether.
Answer: A

Question. Increasing order of acid strength among p-methoxyphenol, p-methylphenol and p-nitrophenol is
(a) p-nitrophenol, p-methoxyphenol, p-methylphenol
(b) p-methylphenol, p-methoxyphenol, p-nitrophenol
(c) p-nitrophenol, p-methylphenol, p-methoxyphenol
(d) p-methoxyphenol, p-methylphenol, p-nitrophenol. 
Answer: D

Question. Which one of the following on oxidation gives a ketone?
(a) Primary alcohol
(b) Secondary alcohol
(c) Tertiary alcohol
(d) All of these 
Answer: B

Question. What is formed when a primary alcohol undergoes catalytic dehydrogenation?
(a) Aldehyde
(b) Ketone
(c) Alkene
(d) Acid 
Answer: A

Question. How many isomers of C₅H₁₁OH will be primary alcohols?
(a) 5
(b) 4
(c) 2
(d) 3
Answer: B

Question. HBr reacts fastest with
(a) 2-methylpropan-1-ol
(b) methylpropan-2-ol
(c) propan-2-ol
(d) propan-1-ol. 
Answer: B

Question. When phenol is treated with excess bromine water. It gives
(a) m-bromophenol
(b) o- and p-bromophenols
(c) 2,4-dibromophenol
(d) 2,4,6-tribromophenol. 
Answer: D

Question. The compound which reacts fastest with Lucas reagent at room temperature is
(a) butan-1-ol
(b) butan-2-ol
(c) 2-methylpropan-1-ol
(d) 2-methylpropan-2-ol. 
Answer: D

Question. Which one of the following compounds will be most readily attacked by an electrophile?
(a) Chlorobenzene
(b) Benzene
(c) Phenol
(d) Toluene 
Answer: C

Question. Propene, CH₃CH CH₂ can be converted into 1-propanol by oxidation. Indicate which set of reagents amongst the following is ideal for the above conversion?
(a) KMnO₄ (alkaline)
(b) Osmium tetroxide (OsO₄/CH₂Cl₂)
(c) B₂H₆ and alk. H₂O₂
(d) O₃/Zn
Answer: C

Question. Phenol is heated with CHCl₃ and aqueous KOH when salicylaldehyde is produced. This reaction is known as
(a) Rosenmund’s reaction
(b) Reimer-Tiemann reaction
(c) Friedel-Crafts reaction
(d) Sommelet reaction. 
Answer: B

Question. Lucas reagent is
(a) conc. HCl and anhydrous ZnCl₂
(b) conc. HNO₃ and hydrous ZnCl₂
(c) conc. HCl and hydrous ZnCl₂
(d) conc. HNO₃ and anhydrous ZnCl₂. 
Answer: A

Question. Methanol is industrially prepared by
(a) oxidation of CH₄ by steam at 900ºC
(b) reduction of HCHO using LiAIH₄
(c) reaction of HCHO with a solution of NaOH
(d) reduction of CO using H₂ and ZnO–Cr₂O₃.
Answer: F

Question. Among the following sets of reactants which one produces anisole?
(a) CH₃CHO ; RMgX
(b) C₆H₅OH ; NaOH ; CH₃I
(c) C₆H₅OH ; neutral FeCl₃
(d) C₆H₅CH₃ ; CH₃COCl ; AlCl₃
Answer: B

Question. Ethyl chloride is converted into diethyl ether by
(a) Perkins reaction
(b) Grignard reaction
(c) Wurtz synthesis
(d) Williamson’s synthesis.
Answer: D

Question. Which one of the following compounds is resistant to nucleophilic attack by hydroxyl ions?
(a) Diethyl ether
(b) Acetonitrile
(c) Acetamide
(d) Methyl acetate
Answer: A

Question. The compound which does not react with sodium is
(a) CH₃COOH
(b) CH₃CHOHCH₃
(c) C₂H₅OH
(d) CH₃OCH₃
Answer: D

Question. Which one is formed when sodium phenoxide is heated with ethyl iodide?
(a) Phenetole
(b) Ethyl phenyl alcohol
(c) Phenol
(d) None of these 
Answer: A

13. Give a chemical test to distinguish between the following pairs of compounds

I. Phenol and cyclohexanol.

II. Propan-2-ol and benzylalcohol.

 

3 Marks Questions

 

14. An organic compound (A) having molecular formula C₆H₆O gives a characteristic colour with aqueous FeCl₃ solution (A) on treatment with CO₂ and NaOH at 400 K under high pressure gives (B) which on acidification gives a compound (C). C reacts with acetyl chloride to give (D), which is a popular Pain Killer. Deduce the structures of (A), (B), (C) and (D).

 

15. Write the chemical equations and reaction conditions for the conversion of

I. Phenol to salicylaldehyde.

II. Methanol to ethanol

III. Anisole to 4-methoxyacetophenone

 

16. Name the reagents for the following

I. Oxidation of primary alcohol to aldehyde.

II. Oxidation of primary alcohol to carboxylic acid.

III. Dehydration of prapan-2-ol to propene.

IV. Reduction of butan-2-one to butan-2-ol.

 

17. Complete the following reaction

18. Compound (A) reacts with SOCl2 to give compound (B). B reacts with Mg to form Grignard reagent which is treated with acetone and the product is hydrolyzed to give 2-methylbutan-2-ol. What are A and B compounds?

 

1 - MARK QUESTIONS

1. What is the main product obtained when vapors of t-butyl alcohol are passed over copper at 300°C ? 1

2. Phenol has smaller dipole moment than methanol. Why ? 1

3.Write the structure of phenetole and give its IUPAC name 1

4. Why are Grignard reagents soluble in ether but not in benzene ? 1

5. Arrange the following compounds in the increasing order of acid strength. Propan-1-ol, 2,4,6-trinitrophenol, 3-nitrophenol, 3,5-dinitrophenol 1

6. Di-tert butyl ether cannot be made by Williamson’s synthesis. Why ? 1

7. Arrange the following alcohols in the order of increasing reactivity towards Lucas reagent

2-butanol, 1-butanol, 2-methyl-2-propanol 1

8. Alcohols acts as weak bases. Why? 1

9. Name the phenol with molecular formula C₇H₈O which on treatment with Br₂ water readily gives a ppt. of C₇H₅OBr₃? 1

10. Phenol is acidic but does not react with NaHCO₃ solution? 1

11.Victor Meyer’s test is carried out for an alcohol which gives blue Colouration, identify type of this alcohol? 1

12. How many ether metamers are represented by C₄H₁₀O ? 1

13. Arrange the following in increasing order of basicity:H₂O,OH-, CH₃OH,CH₃O