Describe a method for refining nickel.

Explanation

To refine nickel, the Mond's process is employed, which consists of two main steps. Here’s a detailed breakdown of the method:

### Step 1: Formation of Nickel Tetracarbonyl
1. **React Nickel with Carbon Monoxide**:
- Nickel (Ni) is heated with carbon monoxide (CO) at a temperature between 330 to 350 Kelvin.
- The reaction can be represented as:
\[
\text{Ni} + 4 \text{CO} \rightarrow \text{Ni(CO)}_4
...