Assertion: Carbylamine reaction involves the reaction between `1^(@)` amine and chloroform in the presence of alkali.
Reason : `1^(@)` -amines are more basic than `2^(@)` -amines.

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion**: The assertion states that the carbylamine reaction involves the reaction of a primary amine with chloroform in the presence of alkali. This is true. The carbylamine reaction is a well-known reaction where a primary amine reacts with chloroform (CHCl3) and a strong base (like KOH) to form an isocyanide (carbylamine).

2. **Mechanism of the Carbylamine Reaction**:
- The primary amine (RNH2) reacts with chloroform in the presence of a strong base (KOH).
- Chloroform generates a dichlorocarbene (CCl2) in the presence of the base.
- The lone pair of electrons on the nitrogen of the primary amine attacks the dichlorocarbene, leading to the formation of an isocyanide (R-N≡C).

3. **Understanding the Reason**: The reason states that primary amines are more basic than secondary amines. This statement is false. While primary amines do have a lone pair of electrons that can be donated, the presence of additional alkyl groups in secondary amines can stabilize the lone pair through hyperconjugation and inductive effects, making them more basic than primary amines.

4. **Conclusion**: The assertion is true, while the reason is false. Therefore, the correct answer to the question is that the assertion is true, but the reason is false.