In borax bead test, which compound (s)is/are not formed?

Options

A. Orthoborate
B. Metaborate
C. Double oxide
D. Tetraborate

Answer

To answer the question regarding which compounds are not formed in the borax bead test, we can break down the process step by step.

### Step 1: Understanding Borax
Borax is a compound with the formula Na2B4O7·10H2O. When heated, it loses water and decomposes to form sodium metaborate and boric oxide.

### Step 2: Heating Borax
When borax is heated, the following reaction occurs:
\[ \text{Na}_2\text{B}_4\text{O}_7 \cdot 10\text{H}_2\text{O} \rightarrow \text{Na}_2\text{B}_4\text{O}_7 + 10\text{H}_2\text{O} \]
This indicates that water is removed, and we are left with anhydrous borax.

### Step 3: Formation of Products
Upon further heating, the anhydrous borax decomposes to form:
\[ \text{Na}_2\text{B}_4\text{O}_7 \rightarrow 2\text{NaBO}_2 + \text{B}_2\text{O}_3 \]
Here, sodium metaborate (NaBO2) and boric oxide (B2O3) are formed.

### Step 4: Identifying Compounds Not Formed
From the reactions above, we can identify the compounds that are not formed during the borax bead test:
1. **Ortho Borate**: This compound is not formed in the borax bead test.
2. **Double Oxide**: This compound is also not formed.
3. **Tetra Borate**: This compound is not formed either.

### Conclusion
Thus, the compounds that are not formed in the borax bead test are:
- Ortho Borate
- Double Oxide
- Tetra Borate

### Final Answer
The compounds that are not formed in the borax bead test are ortho borate, double oxide, and tetra borate.

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