`NH_(3)` solution was added to four semple solution in difference test tube and found the following observation about the precipitate.
a. White ppt which is solution in oxcess of `NH_(3)` solution
b.On heating which is white in cold but yellow on heating
c. The cation present in (b) forms white ppt , with hypo solution which give black ppt on heating
d. The cation present in (c ) forms soluble complex with excess of `NH_(3)` solution
White ppts in (a),(b) and (c ) respectively obtained are

Options

A. `Zn(OH)_(2),Zn(OH)_(2),HgOHg(NH_(2))NO_(3)`
B. `Cd(OH)_(2),Zn(OH)_(2),HgOHg(NH_(2))NO_(3)`
C. `HgOHg(NH_(2))NO_(3)Zn(OH)_(2),Cd(OH)_(2)`
D. `AI(OH)_(2),Zn(OH)_(2),Pb(OH)_(2)`

Explanation

To solve the problem step by step, we will analyze each test tube based on the observations provided and identify the compounds responsible for the white precipitates.

### Step 1: Analyze Test Tube A
- **Observation**: White precipitate which is soluble in excess NH₃ solution.
- **Analysis**: The white precipitate that dissolves in excess NH₃ indicates the presence of either cadmium ions (Cd²⁺) or zinc ions (Zn²⁺).
- **Conclusion**: The white precipitate in Test Tube A is likely **Cadmium Hydroxide (Cd(OH)₂)** or **Zinc Hydroxide (Zn(OH)₂)**.

### Step 2: Analyze Test Tube B
- **Observation**: White precipitate that is white in cold but yellow on heating.
- **Analysis**: This behavior is characteristic of zinc hydroxide (Zn(OH)₂), which is white when cold and turns yellow when heated due to the formation of zinc oxide (ZnO).
- **Conclusion**: The white precipitate in Test Tube B is **Zinc Hydroxide (Zn(OH)₂)**.

### Step 3: Analyze Test Tube C
- **Observation**: The cation present forms a white precipitate with hypo solution, which gives a black precipitate on heating.
- **Analysis**: The cation that fits this description is mercuric ion (Hg²⁺), which forms a white precipitate of mercuric hydroxide (Hg(OH)₂) with NH₃. When treated with hypo (thiosulfate), it forms mercuric thiosulfate (Hg₂S₂O₃), which on heating gives a black precipitate of mercuric sulfide (HgS).
- **Conclusion**: The white precipitate in Test Tube C is **Mercuric Hydroxide (Hg(OH)₂)**.

### Final Summary of White Precipitates
- **Test Tube A**: Cadmium Hydroxide (Cd(OH)₂) or Zinc Hydroxide (Zn(OH)₂)
- **Test Tube B**: Zinc Hydroxide (Zn(OH)₂)
- **Test Tube C**: Mercuric Hydroxide (Hg(OH)₂)