Which of the following processes is endothermic?

Options

A. Burning of coal
B. Rusting
C. Freezing
D. Melting

Answer

To determine which of the following processes is endothermic, we need to understand what an endothermic process is. An endothermic process is one that absorbs heat energy from its surroundings.

**Step-by-step solution:**

1. **Understanding Endothermic Processes**:
- An endothermic process absorbs heat energy. This means that for the reaction or process to occur, heat must be supplied from the surroundings.

2. **Evaluating the Given Processes**:
- **Burning of Coal**: This process involves the combustion of carbon in the presence of oxygen, producing carbon dioxide and releasing a large amount of heat. Since heat is released, this is an exothermic process, not endothermic.

- **Rusting of Iron**: Rusting occurs when iron reacts with oxygen in the air to form iron oxide. Although the heat release is not noticeable, rusting is still an exothermic process because it releases heat.

- **Freezing of Water**: Freezing is the process where a liquid turns into a solid. During freezing, heat is released into the surroundings as the molecules lose energy. Therefore, freezing is an exothermic process.

- **Melting of Ice**: Melting is the process where a solid (ice) turns into a liquid (water). For this process to occur, heat must be absorbed from the surroundings to break the bonds in the solid state. Thus, melting is an endothermic process.

3. **Conclusion**:
- Among the processes evaluated, the melting of ice is the only endothermic process. Therefore, the correct answer is the melting of ice.

**Final Answer**: The endothermic process is melting of ice.

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