Which of the following salts is used in the bead test for basic character ?

Options

A. `Na(NH_4)HPO_4. 4H_2O`
B. `Na_2HPO_4`
C. `(NH_4)_2SO_4.FeSO_4.6H_2O`
D. `(NH_3)_2HPO_4.2H_2O`

Answer

To solve the question regarding which salt is used in the bead test for basic character, we can follow these steps:

### Step 1: Understand the Bead Test
The bead test, also known as the borax bead test, is a qualitative analysis method used to identify certain metal ions based on the color of the bead produced when the salt is heated in a flame.

**Hint:** Remember that the bead test specifically involves borax and is used to identify metal ions.

### Step 2: Identify the Components of the Bead Test
The borax bead test involves borax (sodium borate), which is a glassy substance that can form a bead when heated. The test is performed by mixing the borax with the salt in question and then heating it.

**Hint:** Borax is a key component in this test, and it reacts with metal salts to produce colored beads.

### Step 3: Recognize the Role of Microcosmic Salt
Microcosmic salt, also known as sodium ammonium hydrogen phosphate (NaNH4HPO4·4H2O), is specifically mentioned in the context of the bead test. It is known for its basic character and is used in the borax bead test.

**Hint:** Look for salts that are known to be basic in character, as they are typically involved in this test.

### Step 4: Evaluate the Options
Given the options, we need to identify which one corresponds to microcosmic salt or is commonly used in the bead test. The correct answer is the one that matches the description of microcosmic salt.

**Hint:** Check the chemical formula of the options provided to find the one that matches NaNH4HPO4·4H2O.

### Conclusion
Based on the analysis, the salt used in the bead test for basic character is **microcosmic salt (NaNH4HPO4·4H2O)**.

**Final Answer:** The correct answer is option number one, which corresponds to microcosmic salt.

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