Which of the following is incorrect about borax?

Options

A. Produce alkaline solution in water
B. Produce glassy mass on heating
C. Produce blue bead on heating with `CaSO_(4)`
D. None of these

Explanation

To solve the question regarding which statement about borax is incorrect, let's analyze each statement step by step.

### Step 1: Identify Borax
Borax is chemically known as sodium tetraborate and has the formula Na2B4O7·10H2O.

### Step 2: Analyze the Statements
We have four statements to evaluate:

1. **Borax produces an alkaline solution when dissolved in water.**
- When borax (Na2B4O7·10H2O) dissolves in water, it dissociates to form sodium hydroxide (NaOH) and boric acid (H3BO3). The presence of NaOH indicates that the solution is alkaline.
- **Conclusion:** This statement is correct.

2. **Borax produces a glassy mass on heating.**
- Upon heating, borax loses water and converts to Na2B4O7. Further heating leads to the formation of sodium metaborate (NaBO2) and boron trioxide (B2O3), which together form a glassy mass.
- **Conclusion:** This statement is correct.

3. **Borax produces a blue bead on heating with CaSO4.**
- The blue bead test is typically associated with copper compounds, not calcium. When borax is heated with copper sulfate (CuSO4), it produces a blue bead due to the formation of copper metaborate (CuBO2).
- **Conclusion:** This statement is incorrect because borax does not produce a blue bead with CaSO4.

4. **Borax can be used in the bead test with colored salts.**
- This statement is generally true as borax can be used in the bead test, but it specifically gives a blue bead with copper salts, not calcium salts.
- **Conclusion:** This statement is correct.

### Final Answer
The incorrect statement about borax is: **"It produces a blue bead on heating with CaSO4."**

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