A non-elastic, hard material knownas ebonite is formed when crude rubber is heated with

Options

A. 5% of sulphur
B. 20% of sulphur
C. 30% of sulphur
D. 40-50% of sulphur

Answer

To solve the question regarding the formation of ebonite from crude rubber, we can follow these steps:

### Step 1: Understand the Composition of Crude Rubber
Crude rubber is a natural polymer that can undergo various chemical reactions when heated with different amounts of sulfur.

**Hint:** Consider the role of sulfur in modifying the properties of rubber.

### Step 2: Identify the Reaction with Sulfur
When crude rubber is heated with sulfur, it undergoes a process called vulcanization. The amount of sulfur used in this process determines the properties of the resulting material.

**Hint:** Recall the different percentages of sulfur and their corresponding products.

### Step 3: Analyze the Different Percentages of Sulfur
- **5% Sulfur:** Forms rubber bands, which are elastic.
- **20% Sulfur:** Forms tires for cars and motorbikes, which are more durable but still somewhat elastic.
- **30% Sulfur:** Produces hard tires, suitable for trucks, indicating increased hardness.
- **40-50% Sulfur:** This range leads to the formation of ebonite, a very hard and non-elastic material.

**Hint:** Think about how increasing sulfur content affects the elasticity and hardness of the rubber.

### Step 4: Conclude the Correct Answer
Based on the analysis, the correct answer to the question is that ebonite is formed when crude rubber is heated with **40 to 50% sulfur**.

**Final Answer:** The correct option is 4th option: 40 to 50% sulfur.