If matel ions of group II are precipitate by `NH_(4)CI` and `NH_(4)OH` without prior oxidation by conconirated `HNO_(3)` _____is not completely precipitate

Explanation

To solve the question regarding which metal ion of group II is not completely precipitated by NH₄Cl and NH₄OH without prior oxidation by concentrated HNO₃, we can follow these steps:

### Step-by-Step Solution:

1. **Identify Group II Metal Ions**:
The metal ions of group II in qualitative analysis typically include ions such as Bismuth (Bi³⁺), Cadmium (Cd²⁺), and Mercury (Hg²⁺).

2. **Understand the Precipitation Process**:
NH₄Cl (ammonium chloride) and NH₄OH (ammonium hydroxide) are used to precipitate metal ions from solution. When these reagents are added, they can form insoluble hydroxides or chlorides of certain metal ions.

3. **Consider the Role of Concentrated HNO₃**:
Concentrated nitric acid (HNO₃) is often used to oxidize certain ions. For example, ferrous ions (Fe²⁺) can be oxidized to ferric ions (Fe³⁺) in the presence of concentrated HNO₃.

4. **Identify which Ion is not Completely Precipitated**:
In this case, when NH₄Cl and NH₄OH are added without the prior oxidation step, the presence of Fe³⁺ ions (which can be formed from Fe²⁺) is significant. The ferric ion (Fe³⁺) does not precipitate completely under these conditions because it can remain in solution due to its solubility.

5. **Conclusion**:
Therefore, the metal ion that is not completely precipitated when using NH₄Cl and NH₄OH without prior oxidation by concentrated HNO₃ is **Fe³⁺** (ferric ion).

### Final Answer:
**Fe³⁺ is not completely precipitated.**

---