Home
Class 12
CHEMISTRY
Compound 'A' of molecular formula C(4)H(...

Compound 'A' of molecular formula `C_(4)H_(10)O` on treatment with Lucas reagent at room temperature gives compound 'B'. When compound 'B' is heated with alcoholic KOH, it gives isobutene. Compound 'A' and 'B' are respectively `:`

A

2-Methyl -2-propanol and 2-Methyl -2-chloropropane

B

2-Methyl-1-propanol and 1-Chloro-2-methylpropane

C

2-Methyl-1-propanol and 2-Methyl-2-chloropropane

D

Butan-2-ol and 2-Chlorobutane

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question, we need to identify the compounds 'A' and 'B' based on the given information about their molecular formula and reactions with Lucas reagent and alcoholic KOH. ### Step-by-Step Solution: 1. **Identify Compound A**: - We know that compound 'A' has the molecular formula \( C_4H_{10}O \). - Since it reacts with Lucas reagent at room temperature to form compound 'B' immediately, compound 'A' must be a tertiary alcohol (as tertiary alcohols react quickly with Lucas reagent). 2. **Determine the Structure of Compound A**: - The only tertiary alcohol with the formula \( C_4H_{10}O \) is **2-methyl-2-propanol** (also known as tert-butanol). - Its structure is: \[ \text{(CH}_3)_3\text{C-OH} \] 3. **Reaction with Lucas Reagent**: - When 2-methyl-2-propanol reacts with Lucas reagent (which is a mixture of concentrated HCl and ZnCl2), it converts the -OH group into a -Cl group, forming **2-chloro-2-methylpropane** (compound 'B'). - The reaction can be represented as: \[ \text{(CH}_3)_3\text{C-OH} + HCl \rightarrow \text{(CH}_3)_3\text{C-Cl} + H_2O \] 4. **Heating Compound B with Alcoholic KOH**: - When compound 'B' (2-chloro-2-methylpropane) is heated with alcoholic KOH, it undergoes elimination (dehydrohalogenation) to form isobutene (2-methylpropene). - The reaction can be represented as: \[ \text{(CH}_3)_3\text{C-Cl} + KOH \rightarrow \text{(CH}_3)_2\text{C=CH}_2 + KCl + H_2O \] 5. **Conclusion**: - Based on the above analysis, we conclude that: - Compound A is **2-methyl-2-propanol**. - Compound B is **2-chloro-2-methylpropane**. ### Final Answer: Compound 'A' and 'B' are respectively **2-methyl-2-propanol** and **2-chloro-2-methylpropane**. ---
Promotional Banner

Similar Questions

Explore conceptually related problems

The compound that reacts fastest with Lucas reagent at room temperature is

An aromatic compound 'A' having molecular formula C_(7)H_(6)O_(2) on treating with aqueous ammonia and heating forms compound 'B'. The compound 'B' on reaction with molecular bromine and potassium hydroxide provides compound 'C' having molecular formula C_(6)H_(7)N . The structure of 'A' is

A compound 'A' when reacts with LiAlH_4 it gives two compounds B and C along with LiCl. Compounds A, B and C respectively are

A compound (A) with molecular formula C_(5) H_(10) gives one monochlorination product. Compound (A) is:

An organic compound with molecular formula C_6 H_(12) upon ozonolysis gives only acetone as the product. The compound is :

An organic compound [A] having molecular formula C_2 H_7 N on treatment with nitrous acid gives a compound [B] having molecular formula C_2 H_6 O .[B] on treatment with an organic compound (C) gives a carboxylic acid [D] and a sweet smelling compound (E). Oxidation of [B] with acidified potassium dichromate also gives [D]. Identify [A], [B], [C], [D] and [E].

An aromatic compound 'A' (Molecular formula C_(8)H_(8)O) ) gives positive 2, 4-DNP test. It gives a yellow precipitate of compound 'B' on treatment with iodine and sodium hydroxide solution. Compound 'A' does not give Tollen's or Fehling's test. On drastic oxidation with potassium permanganate, it forms a carboxylic acid 'C' (Molecular formula C_(7)H_(6)O_(2) ), which is also formed along with the yellow compound in the above reaction. Identify A, B and C and write all the reactions involved.

An organic compound [A] having molecular formula C_2 H_7 N on treatment with nitrous acid gives a compound [B] having molecular formula C_2 H_6 O .[B] on treatment with an organic compound (C) gives a carboxylic acid [D] and a sweet smelling compound (E). Oxidation of [B] with acidified potassium dichromate also gives [D]. Write balanced chemical equation of [D] with chlorine in the presence of red phosphorus and name the reaction.