The ion that cannot be precipitate by both HCI and `H_(2)S` is

Options

A. `Pb^(2+)`
B. `Cu^(o+)`
C. `Ag^(o+)`
D. `Sn^(2+)`

Explanation

To solve the question "The ion that cannot be precipitated by both HCl and H2S is," we will analyze the behavior of different ions in the presence of these reagents.

### Step-by-Step Solution:

1. **Understand the Reagents**:
- **HCl (Hydrochloric Acid)**: It is a strong acid that can precipitate certain metal ions by forming insoluble chlorides.
- **H2S (Hydrogen Sulfide)**: This reagent is used to precipitate metal ions as sulfides, which are often insoluble.

2. **Identify the Ions**:
- We need to consider common metal ions that are typically tested in qualitative analysis, such as Ag⁺ (Silver), Pb²⁺ (Lead), Cu²⁺ (Copper), and others.

3. **Reactivity of Silver Ion (Ag⁺)**:
- The silver ion (Ag⁺) is known to form a precipitate with HCl, resulting in the formation of silver chloride (AgCl), which is insoluble in water.
- However, Ag⁺ does not precipitate with H2S. Silver sulfide (Ag2S) is not formed under normal conditions with H2S.

4. **Reactivity of Other Ions**:
- Most other metal ions, such as Pb²⁺, Cu²⁺, and others, can be precipitated by H2S in the presence of HCl.
- For example, lead (Pb²⁺) can form lead sulfide (PbS) when treated with H2S.

5. **Conclusion**:
- Since Ag⁺ is the only ion that cannot be precipitated by both HCl and H2S, we conclude that the answer to the question is **Ag⁺ (Silver ion)**.

### Final Answer:
The ion that cannot be precipitated by both HCl and H2S is **Ag⁺ (Silver ion)**.