Match the salts listed in column I with the colour of the precipitate and reagent listed in column II.
`{:("Column I","Column II"),((A)FeSO_4,(p)"Green precipitate with NaOH"),((B)Bi(NO_3)_3,(q)"White precipitate with" Pb(NO_3)_2),(( C)Ni(NO_3)_2,(r)"Yellow precipitate with"NH_4NO_2 and CH_3COOH "on warming"),((D)CoCl_2,(s)"Black precipitate with"H_2S),(,(t)"White precipitate with excess of water"):}`

Explanation

To solve the problem of matching the salts in Column I with the corresponding color of the precipitate and reagent in Column II, we will analyze each salt and its reactions step by step.

### Step 1: Analyze FeSO₄ (Ferrous Sulfate)
- **Reaction with NaOH**: When FeSO₄ reacts with NaOH, it forms a green precipitate of ferrous hydroxide (Fe(OH)₂).
- **Match**: This corresponds to (p) "Green precipitate with NaOH".

### Step 2: Analyze Bi(NO₃)₃ (Bismuth Nitrate)
- **Reaction with H₂S**: When Bi(NO₃)₃ reacts with H₂S, it forms a black precipitate of bismuth sulfide (Bi₂S₃).
- **Reaction with excess water**: When Bi(NO₃)₃ is treated with excess water, it forms a white precipitate of bismuth hydroxide (Bi(OH)₃).
- **Match**: This corresponds to (q) "White precipitate with Pb(NO₃)₂" and (s) "Black precipitate with H₂S".

### Step 3: Analyze Ni(NO₃)₂ (Nickel Nitrate)
- **Reaction with H₂S**: When Ni(NO₃)₂ reacts with H₂S, it forms a black precipitate of nickel sulfide (NiS).
- **Match**: This corresponds to (s) "Black precipitate with H₂S".

### Step 4: Analyze CoCl₂ (Cobalt Chloride)
- **Reaction with NH₄NO₂ and CH₃COOH**: When CoCl₂ reacts with ammonium nitrate and acetic acid, it forms a yellow precipitate of a coordination complex.
- **Reaction with H₂S**: When CoCl₂ reacts with H₂S, it forms a black precipitate of cobalt sulfide (CoS).
- **Match**: This corresponds to (r) "Yellow precipitate with NH₄NO₂ and CH₃COOH" and (s) "Black precipitate with H₂S".

### Final Matching:
- A (FeSO₄) → (p) "Green precipitate with NaOH"
- B (Bi(NO₃)₃) → (q) "White precipitate with Pb(NO₃)₂" and (s) "Black precipitate with H₂S"
- C (Ni(NO₃)₂) → (s) "Black precipitate with H₂S"
- D (CoCl₂) → (r) "Yellow precipitate with NH₄NO₂ and CH₃COOH" and (s) "Black precipitate with H₂S"

### Summary of Matches:
- A → p
- B → q, s
- C → s
- D → r, s