Initiators that can be used in cationic polymerization is/are
(a) `KNH_(2)` (b) `H_(2)SO_(4)`
(c) `BF_(3)` with little amount of `H_(2)O` (d) t-butyl peroxide
The correct answer is

Options

A. All are correct
B. only a
C. only b and c
D. only a and d

Answer

To determine which initiators can be used in cationic polymerization, we need to analyze each option provided in the question.

### Step 1: Understand Cationic Polymerization
Cationic polymerization is a type of chain-growth polymerization that involves the formation of a positively charged ion (cation) which initiates the polymerization process. This process typically requires an initiator that can generate cations or proton donors.

### Step 2: Analyze Each Option
- **(a) `KNH_(2)` (Potassium Amide)**: This compound is a strong base and does not act as a cationic initiator. Instead, it would deprotonate and not facilitate cationic polymerization. **(Not suitable)**

- **(b) `H_(2)SO_(4)` (Sulfuric Acid)**: This is a strong acid that can donate protons, thus generating cations. It can effectively initiate cationic polymerization. **(Suitable)**

- **(c) `BF_(3)` with a little amount of `H_(2)O` (Boron Trifluoride)**: BF3 is a Lewis acid and can accept electron pairs, which makes it a suitable initiator for cationic polymerization when mixed with water, as water can provide protons. **(Suitable)**

- **(d) t-butyl peroxide**: This compound is a radical initiator and is typically used in free radical polymerization, not cationic polymerization. **(Not suitable)**

### Step 3: Conclusion
From the analysis:
- Suitable initiators for cationic polymerization are **(b) `H_(2)SO_(4)`** and **(c) `BF_(3)` with a little amount of `H_(2)O`**.

Thus, the correct answer is **(b) and (c)**.

### Final Answer:
The correct initiators that can be used in cationic polymerization are **(b) `H_(2)SO_(4)` and (c) `BF_(3)` with little amount of `H_(2)O`**.

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