Q.Assertion: Hoffmann's bromamide reaction is given by primary amines.
Reason: Primary amines are more basic than secondary amines.

The key idea here is to check the factual accuracy of both statements independently, then see if the reason explains the assertion.

Step 1 – Assertion check: Hoffmann’s bromamide reaction (Hofmann rearrangement) converts a primary amide into a primary amine with one fewer carbon. It is not given by primary amines — it produces them. So the assertion is wrong. …

Let’s unpack this carefully — the question tests two separate ideas: the Hoffmann bromamide reaction and the basicity order of amines. Each needs to be examined on its own merit.

1. What is the Hoffmann bromamide reaction?

This is a classic name reaction where an amide ($\ce{RCONH2}$) is treated with bromine and a strong base (like $\ce{NaOH}$) to give a primary amine with one fewer carbon atom. The reaction proceeds through a rearrangement (the Hofmann rearrangement) and is famously not given by amines themselves. The starting material must be an amide, not an amine.

So the assertion says: "Hoffmann's bromamide reaction is given by primary amines." That is factually incorrect. Primary amines are the product of the reaction, not the reactant. The assertion is wrong.

2. What about the basicity of primary vs secondary amines?

Basicity depends on the availability of the lone pair on nitrogen for protonation. In the gas phase, alkyl groups are electron-donating (through the inductive effect), so more alkyl groups on nitrogen increase electron density and thus basicity. The order in the gas phase is:

However, in aqueous solution, solvation effects complicate things. The ammonium cation formed after protonation is stabilized by hydrogen bonding with water. More hydrogen atoms on the nitrogen (as in primary amines) allow better solvation, but this does not make primary amines the most basic — for simple alkyl amines the commonly taught aqueous order is:

$\text{secondary} > \text{primary} > \text{tertiary} > \text{ammonia}$ …

Concept: Hoffmann Bromamide Reaction & Basicity of Amines

Method: Factual Verification + Logical Linkage Check

This is a standard assertion-reason problem. The method is to:

1. Verify the Assertion independently.
2. Verify the Reason independently.
3. Check if the Reason correctly explains the Assertion.

Step 1: Verify the Assertion

Assertion: Hoffmann's bromamide reaction is given by primary amines.

• Fact: Hoffmann bromamide degradation is a reaction where a primary amide (RCONH₂) is treated with bromine and a strong base (NaOH/KOH) to give a primary amine with one less carbon atom.
• The reactant is an amide, not an amine. The product is a primary amine.
• Therefore, the assertion is wrong — primary amines do not give this reaction; they are produced by it.

Result: Assertion is false.

Step 2: Verify the Reason

Reason: Primary amines are more basic than secondary amines.

• Fact: In aqueous solution, the order of basicity for aliphatic amines is: …

Here are the common mistakes students make with this Assertion-Reason question, along with how to avoid each.

Mistake 1: Confusing the Reactant in Hoffmann Bromamide Reaction

The Mistake: Students often think the reaction starts with a primary amine (R-NH₂). They see "Hoffmann's bromamide reaction is given by primary amines" and assume it's correct because the product is a primary amine.

The Correction: The reactant is an amide (R-CONH₂), not an amine. The reaction converts an amide into a primary amine with one less carbon atom.

• Reactant: Amide ($\ce{R-CONH2}$)
• Reagent: Bromine ($\ce{Br2}$) in aqueous/alkaline medium ($\ce{NaOH}$)
• Product: Primary amine ($\ce{R-NH2}$)

How to Avoid: Memorize the exact starting material. Write the reaction equation every time you revise:

Mistake 2: Misjudging the Assertion's Truth Value

The Mistake: Because the reactant is an amide, students incorrectly mark the Assertion as "wrong."

The Correction: The Assertion says: "Hoffmann's bromamide reaction is given by primary amines." This is false. The reaction is given by amides, not amines. The product is a primary amine, but the reactant is not.

How to Avoid: Read Assertions literally. The statement says the reaction is "given by" (i.e., performed on) primary amines. That is incorrect. Do not confuse the product with the reactant.

Mistake 3: Assuming All Amines are More Basic Than Others

The Mistake: Students accept the Reason ("Primary amines are more basic than secondary amines") as correct without checking the actual trend.

The Correction: In aqueous solution, the basicity order is:

So, secondary amines are more basic than primary amines. The Reason is wrong.

How to Avoid: Memorize the correct order. Use the logic of inductive effect and solvation:

• Alkyl groups are electron-donating (+I effect), which increases electron density on nitrogen.
• More alkyl groups = more electron density = stronger base (in gas phase).
• In water, solvation of the conjugate acid matters. Tertiary amines have poor solvation, so secondary amines win in aqueous medium.

Mistake 4: Choosing Option (B) — "Both correct, Reason not the explanation"

The Mistake: Students think both statements are true but unrelated, so they pick (B).

The Correction: Both statements are actually false, so (B) is invalid. Evaluate each part independently:

• Assertion: "Hoffmann's bromamide reaction is given by primary amines." → False (it is given by amides).
• Reason: "Primary amines are more basic than secondary amines." → False (secondary amines are more basic in aqueous medium).

Both statements are wrong, so the correct answer is (A) Both assertion and reason are wrong. …