Explain these points given below.
Coke is sometimes perferred over coal as a fuel.

Explanation

**Step-by-Step Solution:**

1. **Definition of Coke and Coal:**
- Coke is a solid carbonaceous material derived from the destructive distillation of coal. It is primarily used in the production of steel and as a fuel.
- Coal is a natural fossil fuel that is mined from the earth and is composed of carbon, hydrogen, sulfur, oxygen, and nitrogen.

2. **Calorific Value:**
- The calorific value is the amount of energy produced when a substance is burned. It is usually measured in kilojoules per kilogram (kJ/kg).
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