Which of the following statement is correct about Bakellite?

Options

A. It is a cross linked polymer
B. It is an addition polymer
C. It is a branched chain polymer
D. It is a linear polymer

Answer

To determine which statement is correct about Bakelite, we will analyze the properties and formation of Bakelite step by step.

### Step 1: Understanding the Composition of Bakelite
Bakelite is a type of polymer that is formed from the reaction of phenol and formaldehyde. These two compounds serve as the monomers for the polymerization process.

**Hint:** Identify the monomers involved in the formation of Bakelite.

### Step 2: Polymerization Process
The polymerization of Bakelite involves two main stages:
1. **Formation of Novolac:** Initially, phenol reacts with formaldehyde in the presence of an acid catalyst to form a prepolymer called Novolac. This reaction typically involves an excess of formaldehyde.
2. **Cross-linking:** Upon heating, the Novolac undergoes further reactions where it cross-links, leading to the formation of Bakelite. During this process, water is eliminated, which is characteristic of condensation reactions.

**Hint:** Understand the two stages of polymerization: initial formation and cross-linking.

### Step 3: Identifying the Type of Polymer
Bakelite is classified as a thermosetting polymer due to its cross-linked structure. This means that once it is set, it cannot be remolded or reshaped. The cross-linking gives Bakelite its strength and heat resistance.

**Hint:** Consider the characteristics of thermosetting polymers compared to thermoplastics.

### Step 4: Evaluating the Statements
Now we can evaluate the statements provided in the question:
1. **It is a cross-linked polymer.** - This statement is correct.
2. **It is an addition polymer.** - This statement is incorrect because Bakelite is formed through a condensation reaction, not an addition reaction.
3. **It is a branched polymer.** - This statement is also incorrect, as Bakelite has a network structure due to cross-linking.

**Hint:** Compare the definitions of cross-linked, addition, and branched polymers to determine the correct statement.

### Conclusion
The correct statement about Bakelite is that it is a **cross-linked polymer**.