Magneson reagent is used to detect

Options

A. `Mn^2+`
B. `Mg^(2+)`
C. `PO_(4)^(3-)`
D. `MnO_(4)^(-)`

Answer

To solve the question regarding the use of Magneson reagent, we will follow these steps:

### Step 1: Understand the Magneson Reagent
Magneson reagent, scientifically known as 4-(4-nitrophenylazo) resorcinol, has the chemical formula C12H9N3O4. It is a specific reagent used in qualitative analysis.

**Hint:** Familiarize yourself with the chemical structure and properties of Magneson reagent.

### Step 2: Identify the Purpose of Magneson Reagent
The primary use of Magneson reagent is to detect the presence of magnesium ions (Mg²⁺) in a solution. This reagent forms a colored complex with magnesium ions.

**Hint:** Look for specific ions that are commonly detected by various reagents in qualitative analysis.

### Step 3: Analyze the Options Given
The options provided are:
1. Mn²⁺ (Manganese ions)
2. Mg²⁺ (Magnesium ions)
3. PO₄³⁻ (Phosphate ions)
4. MnO₄⁻ (Permanganate ions)

From our knowledge of Magneson reagent, we can eliminate the other options as they do not correspond to magnesium detection.

**Hint:** Cross-reference the ions listed with the known uses of the reagents to narrow down the correct answer.

### Step 4: Confirm the Detection of Magnesium Ions
When Magneson reagent is added to a solution containing Mg²⁺ ions, it produces a deep blue color, confirming the presence of magnesium.

**Hint:** Remember that color changes are often indicative of specific reactions in qualitative analysis.

### Step 5: Conclusion
Based on the information gathered, the correct answer to the question is that Magneson reagent is used to detect Mg²⁺ ions.

**Final Answer:** The correct option is **2. Mg²⁺**.