Alcohols, Phenols & Ethers

Alcohols, Phenols & Ethers
Class:XII / Unit:11

1. Which of the following alcohols gives 2-butenc on dehydration byconc. H₂SO₄?

Butane-2-ol
Butane 1-ol
2-methyl 1 -propanol
2-methyl propene-2-ol

2. One mole of ethyl acetate on tatment with an excess of LiAlH₄ in dry ether and subsequent acidification produces

1 mole of 2-butanol
2 moles of ethyl alcohol
1 mole acetic acid + 1 mole ethyl alcohol
1 mole ethyl alcohol + 1 mole methyl alcohol

3. 1-Phenylethanol can be prepared by the reaction of benzaldehyde with

methyl bromide
methyl iodide and magnesium (Grignard reagent’s)
ethyl iodide and magnesium
methyl bromide and aluminium bromide

4. Which of the following alcohols will give the most stable carbocation during dehydration?

2-methyl-1-propanol
2-Butanol
1-Butanol
2-methyl-2-propanol

5. Order of esterification of alcohols are

3° > 1° > 2°
1 ° > 2° > 3°
2°> 3° > 1°
None of these

6. What happens when tertiary butyl alcohol is passed over heated copper at 300°C?

Secondary butyl alcohol is formed
2-methylpropene is formed
1-butene is formed
Butanol is formed

7. What would be the reactant and reagent used to obtain 2, 4-dimenthyl pentan-3-ol?

2-methylpropanal and isopropyl magnesium iodide
Propanal and propyl magnesium bromide
2-methylpropanal and isopropyl magnesium iodide
2-dimethylpropanone and methyl magnesium odide

8. The decreasing order of boiling point of the following alcohols is

3-methylbuan-2-ol > 2-methylbutan-2-ol > pentan-1-ol
Pentan-1-ol > 3-methylbutan-2-ol > 2-methylbutan-2-ol
2-methylbutan-2-ol > 3-methylbutan-2-ol > pentan-1-ol
2-methylbutan-2-ol > pental-1-ol > 3-methylbutan-2-ol

9. Acid catalysed dehydration of t-butanol is faster than that of n-butanol because

primary carbocation is more stable than tertiary carbocation
tertiary carbocation is more stable than primary carbocation
t-butanol has a higher boiling point
rearrangement takes place during dehydration of t- butanol

10. Propanone on reaction with alkyl magnesium bromide followed by hydrolysis will produce

tertiary alcohol
Carboxylic acid
secondary alcohol
primary alcohol