In the wet tests for identification of various cations by precipitation, which transition element cation doesn’t belong to group IV in qualitative inorganic analysis ?

Options

A. `Zn^(2+)`
B. `Fe^(3+)`
C. `Ni^(2+)`
D. `Co^(2+)`

Answer

To solve the question regarding which transition element cation does not belong to group IV in qualitative inorganic analysis, we can follow these steps:

### Step 1: Understand the Groups in Qualitative Inorganic Analysis
Qualitative inorganic analysis categorizes cations into groups based on their reactions with specific reagents. Each group has characteristic cations that can be identified through precipitation reactions.

**Hint:** Familiarize yourself with the classification of cations in qualitative analysis and the specific groups they belong to.

### Step 2: Identify Group IV Cations
Group IV in qualitative inorganic analysis typically includes cations such as:
- Zinc (Zn²⁺)
- Nickel (Ni²⁺)
- Cobalt (Co²⁺)

These cations are known to form precipitates with certain reagents used in qualitative tests.

**Hint:** Recall the common cations that are tested in qualitative analysis and their group classifications.

### Step 3: Determine the Cation in Question
The question asks for a transition element cation that does not belong to group IV. We need to consider other transition metal cations that might be relevant.

**Hint:** Think about other transition metals and their common oxidation states.

### Step 4: Identify the Incorrect Cation
Among the transition metal cations, Iron (Fe³⁺) is a common cation that is often tested but does not belong to group IV. Instead, it is typically classified in group III due to its precipitation behavior.

**Hint:** Compare the behavior of transition metal cations in qualitative tests to determine which ones do not fit into group IV.

### Conclusion
The transition element cation that does not belong to group IV in qualitative inorganic analysis is **Fe³⁺ (Iron(III))**.

**Final Answer:** Fe³⁺