In case of condensation of polymers ?

Options

A. High molecular weight polymers are formed all at once.
B. Lower molecular weight polymers are formed all at once.
C. Molecular weight of polymers rises throughout the reaction.
D. Have no specific relation to their molecular weight .

Answer

To solve the question regarding the condensation of polymers, we need to understand the process of condensation polymerization and how it affects the molecular weight of the resulting polymers. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand Condensation Polymerization
Condensation polymerization is a type of polymerization where monomers join together with the elimination of small molecules, often water or methanol. This process typically involves two different types of monomers.

**Hint:** Remember that condensation polymerization involves the loss of small molecules during the formation of larger polymers.

### Step 2: Identify the Monomers
In the example provided, we have two monomers, A and B. These monomers react to form dimers, trimers, and eventually larger polymers through a stepwise process.

**Hint:** Think about how two different monomers can react to form larger structures through repeated reactions.

### Step 3: Step Growth Polymerization
The process described follows a step-growth mechanism, where the molecular weight of the polymer increases gradually as the reaction progresses. Initially, low molecular weight species are formed, and as more reactions occur, the molecular weight continues to rise.

**Hint:** Step-growth polymerization means that the molecular weight increases as the reaction continues, rather than forming high molecular weight polymers all at once.

### Step 4: Molecular Weight Increase
As the reaction continues, the molecular weight of the polymers increases throughout the reaction. This is because each reaction between monomers adds to the overall molecular weight.

**Hint:** Keep track of how each reaction contributes to the overall molecular weight of the polymer.

### Step 5: Analyze the Options
Given the options provided:
1. High molecular weight of polymers are formed all at once.
2. More of the polymers of the molecular weight are formed at the same time.
3. Molecular weight of polymers rises throughout the reaction.
4. Have no specific relation to their molecular weight.

The correct answer is that the molecular weight of polymers rises throughout the reaction.

**Hint:** Look for the option that reflects the continuous increase in molecular weight as the condensation polymerization proceeds.

### Final Answer
The correct option is: **Molecular weight of polymers rises throughout the reaction.**