Which is not the use of orthoboric acid?

Options

A. As an antiseptic and eye wash.
B. In glass industry
C. In glazes for pottery.
D. In borax - bead test

Answer

To determine which option is not a use of orthoboric acid, we can analyze the given options step by step.

### Step 1: Understand Orthoboric Acid
Orthoboric acid, also known as boric acid (H₃BO₃), is a white crystalline solid with various applications in different fields.

### Step 2: Analyze Each Option
1. **As an Antiseptic and Eye Wash**:
- Orthoboric acid is indeed used as an antiseptic for minor cuts and as an eye wash to soothe irritation.
- **Conclusion**: This is a valid use.

2. **In Glass Industry**:
- It is used in the manufacturing of heat-resistant boron silicate glasses.
- **Conclusion**: This is a valid use.

3. **In Glaze**:
- Orthoboric acid is used in pottery as a component in glazes, providing a shiny finish to ceramic items.
- **Conclusion**: This is a valid use.

4. **In Borax Bead Test**:
- The borax bead test is a qualitative test for detecting certain metal ions. It involves heating borax (sodium borate) and does not directly involve orthoboric acid.
- **Conclusion**: This is not a use of orthoboric acid; rather, it is a test involving borax.

### Final Conclusion
Based on the analysis, the option that is **not** a use of orthoboric acid is **Option 4: In Borax Bead Test**.

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