The residue that is left behind when coal is subjected to destructive distillation is called_____

Options

A. Coke
B. Coal gas
C. Peat
D. Coal

Answer

**Step-by-Step Solution:**

1. **Understanding Destructive Distillation**: Destructive distillation is a process where organic materials, like coal, are heated in the absence of air. This prevents combustion and allows the material to break down into various components.

2. **Heating Coal**: In the case of coal, it is heated to a high temperature (around 1000 degrees Celsius) during this process. The absence of air is crucial to avoid burning the coal.

3. **Products of Destructive Distillation**: When coal undergoes destructive distillation, it produces several by-products, including coal tar and coal gas. However, the focus of the question is on the residue left behind.

4. **Identifying the Residue**: The residue that remains after the destructive distillation of coal is known as coke. Coke is a solid carbonaceous material that is left after the volatile components of coal have been driven off.

5. **Composition of Coke**: Coke is primarily composed of carbon, with about 98% carbon content, making it one of the purest forms of carbon available.

6. **Uses of Coke**: Due to its high carbon content, coke is used as a fuel and as a reducing agent in various industrial processes, such as in the production of iron and steel.

7. **Final Answer**: Therefore, the residue that is left behind when coal is subjected to destructive distillation is called **coke**.

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