Alcohols Phenols And Ethers

Step 1: Concept
This conversion is known as the Reimer-Tiemann reaction.
Step 2: Analysis
Phenol reacts with and alkali at .
Step 3: Conclusion
The final product formed is salicylaldehyde.
Final Answer: (B)

Step 1: Concept
Acidity depends on the stability of the conjugate base formed after losing a proton.
Step 2: Analysis
Loss of from phenol results in a phenoxide ion.
Step 3: Conclusion
The negative charge on oxygen in the phenoxide ion is delocalized over the benzene ring via resonance, stabilizing it.
Final Answer: (A)

Step 1: Concept
Acidity depends on the stability of the conjugate base formed after losing a proton.
Step 2: Analysis
Loss of from phenol results in a phenoxide ion.
Step 3: Conclusion
The negative charge on oxygen in the phenoxide ion is delocalized over the benzene ring via resonance, stabilizing it.
Final Answer: (A)

Step 1: Formula
Angle of deviation .
Step 2: Reflection Law
For a plane mirror, . Given , then .
Step 3: Calculation
.
Final Answer: (c)

Step 1: Set up Rate Ratio
Using the general rate law . .
Step 2: Simplify
.
Step 3: Find n
, so .
Final Answer: (d)

Step 1: Formula
Use the Lens maker's formula: .
Step 2: Comparison
In air, . In water, .
Step 3: Result
. Therefore, m.
Final Answer: (d)

Step 1: Analyzing the given statements.
- (1) All alcohols are miscible with water: This statement is incorrect. While lower alcohols (like methanol and ethanol) are miscible with water, higher alcohols (such as octanol) are not miscible with water.
- (2) Only lower alcohols are miscible with water: This statement is correct. The solubility decreases as the molecular weight of the alcohol increases.
- (3) All alcohols are not poisonous: This statement is correct. While ethanol is non-poisonous in moderate amounts, methanol and other alcohols can be poisonous.
- (4) Methanol is poisonous: This statement is correct. Methanol is indeed toxic and can cause blindness or death if ingested.

Step 2: Conclusion.
The correct answer is (1) All alcohols are miscible with water.

Step 1: Understanding the structure of cyclohexanol.
Cyclohexanol is an alcohol with the structure , where the hydroxyl group is attached to a secondary carbon (a carbon bonded to two other carbons).

Step 2: Classification of alcohols.
- (1) Phenol: A phenol is a compound where the hydroxyl group is attached to a benzene ring. This is not the case with cyclohexanol.
- (2) 1° alcohol: A 1° alcohol has the hydroxyl group attached to a primary carbon (a carbon bonded to only one other carbon).
- (3) 2° alcohol: This is the correct classification for cyclohexanol, as the hydroxyl group is attached to a secondary carbon.
- (4) 3° alcohol: A 3° alcohol has the hydroxyl group attached to a tertiary carbon, but cyclohexanol does not fit this description.

Step 3: Conclusion.
The correct answer is (3) 2° alcohol.

Step 1: Understanding the enzymes involved in ethanol production.
Ethanol production from sugar involves the breakdown of sugars (like glucose) by specific enzymes to produce ethanol and carbon dioxide.

Step 2: Identifying the enzymes.
- (1) Diastase and zymase: Diastase is involved in the breakdown of starch into maltose, but not directly in ethanol production.
- (2) Maltase and zymase: Maltase breaks down maltose into glucose, but this isn't the complete enzyme pair for ethanol production.
- (3) Diastase and invertase: Invertase breaks sucrose into glucose and fructose, but this is not the best pairing for ethanol production.
- (4) Invertase and zymase: Invertase breaks down sucrose into glucose and fructose, which can then be fermented by zymase to produce ethanol.

Step 3: Conclusion.
The correct answer is (4) Invertase and zymase.

Step 1: Understanding the Concept:
S 1 reactions give racemisation (via carbocation). S 2 reactions give inversion of configuration.
Step 2: Detailed Explanation:
Formation of A via S 1: carbocation intermediate, attack from either side racemisation.
Formation of B via S 2: backside attack inversion.
Both statements I and II are correct.
Step 3: Final Answer:
Thus, both I and II are correct.

Step 1: Understanding the Concept:
The reaction involves addition of nucleophile to epoxide. Epoxide ring opening gives different products depending on attack site.
Step 2: Detailed Explanation:
Epoxide ring can be opened at either carbon. If the epoxide is unsymmetrical, attack at different positions gives different constitutional isomers. Three distinct substituted alcohols are possible.
Step 3: Final Answer:
Thus, three types of alcohols are obtained.

Step 1: Understanding the Concept:
Orientation in electrophilic aromatic substitution depends on the nature of substituents present on the ring.
Step 2: Detailed Explanation:
From the given structures:
I, II and III are considered to direct the incoming electrophile in such a way that substitution occurs at meta position under the given conditions.
Thus, these compounds show meta substitution.
Step 3: Final Answer:
Thus, NO will be at meta position in I, II and III.

Concept: Hydroquinone is a dihydroxy benzene easily oxidized to quinone.

Step 1: Hydroquinone contains two –OH groups on benzene.

Step 2: It readily loses hydrogen to form quinone structure.

Step 3: Hence it undergoes oxidation easily.
Conclusion:
Most favorable reaction = Oxidation

Concept: Dehydration in acidic medium proceeds via carbocation formation. Stability of carbocation determines ease of dehydration. Additionally, nearby functional groups can stabilize carbocation via resonance.

Step 1: Effect of carbonyl group.
A carbonyl group ( ) adjacent to the carbocation can stabilize it through resonance and electron-withdrawing effects.

Step 2: Compare options.
• (A) Secondary alcohol with nearby carbonyl → extra resonance stabilization → most favorable
• (B) Secondary alcohol → only moderate stability
• (C) Tertiary alcohol → stable, but no additional resonance stabilization
• (D) Diol → follows different dehydration pathway

Step 3: Conclusion.
Due to resonance stabilization by the carbonyl group, option (A) undergoes dehydration most readily.

Concept: 1 mol alcohol gives 1 mol methane.

Step 1: Moles of methane.


Step 2: Moles of alcohol.


Step 3: Molar mass.


Step 4: Identify alcohol.
Molar mass

Concept: Dehydration:

Step 1: Molar masses.


Step 2: Theoretical yield.


Step 3: Actual yield.

Concept: Prefix “neo-” indicates a tert-butyl group .

Step 1: Structure of neo-heptyl alcohol. Heptyl alcohol has 7 carbons. Neo-heptyl alcohol contains group with :

Step 2: Identify correct option. Only option (B) shows tert-butyl group attached to .

Step 3: Conclusion. Option (B) is the correct neo-structure.

Concept: Lucas test:
• Tertiary alcohol fastest reaction
• Secondary alcohol moderate
• Primary alcohol slow

Step 1: Identify alcohol types.
Position 1 primary
Position 6 primary
Position 5 secondary
Position 4 tertiary (attached to three carbons)

Step 2: Apply Lucas rule.
Tertiary alcohol reacts fastest.

Step 3: Conclusion.
Position 4 reacts fastest.

Concept:
•Phenol + Zn dust → benzene
•Friedel-Crafts alkylation → alkyl benzene
•Strong oxidation (KMnO ) → carboxylic acid

Step 1:

Step 2:

Step 3: