The borax bead test can be used to detect the presence of

Options

A. Al
B. Mg
C. Na
D. Fe

Answer

### Step-by-Step Solution:

1. **Understanding the Borax Bead Test**: The borax bead test is a qualitative analysis method used to detect the presence of certain metal ions in a sample. It involves heating borax (sodium borate) to form a glassy bead that can react with metal salts.

2. **Heating Borax**: When borax is heated, it undergoes a transformation:
- Initially, it decomposes to form sodium tetraborate (Na2B4O7).
- Further heating leads to the formation of sodium metaborate and boron trioxide (B2O3), resulting in a glassy bead.

3. **Adding Metal Salts**: A sample containing metal ions (like copper sulfate, iron sulfate, etc.) is then added to the heated borax. The metal salt decomposes upon heating:
- For example, copper sulfate decomposes to form copper oxide (CuO) and sulfur trioxide (SO3).

4. **Formation of Metal Borates**: The metal oxide produced (e.g., CuO) reacts with the boron trioxide (B2O3) in the glassy bead to form metal borates. These metal borates are often colored, which helps in identifying the metal present.

5. **Identifying Colors**: Different metals produce characteristic colors in the borax bead test:
- Copper: Blue
- Iron: Green
- Cobalt: Blue
- Nickel: Brown
- Chromium: Green
- Manganese: Red or Violet

6. **Conclusion**: The borax bead test can be used to detect the presence of various metals, including copper, iron, cobalt, nickel, chromium, and manganese. The specific color observed in the bead indicates which metal is present.

### Final Answer:
The borax bead test can be used to detect the presence of metals such as copper, iron, cobalt, nickel, chromium, and manganese.

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