Cobalt salt+`KNO_(2)+CH_(3)COOHto`yellow ppt.the yellow precipitate is:

Options

A. Potassium cobaltanitrate
B. Potassium cobaltinitrite
C. Cobalt nitrite
D. Cobalt nitrate

Answer

To determine the yellow precipitate formed from the reaction of cobalt salt with potassium nitrite and acetic acid, we can follow these steps:

### Step 1: Identify the Reactants
The reactants in the given reaction are:
- Cobalt salt (which typically contains Co²⁺ ions)
- Potassium nitrite (KNO₂)
- Acetic acid (CH₃COOH)

### Step 2: Understand the Reaction
When cobalt salt (likely cobalt(II) salt) reacts with potassium nitrite in the presence of acetic acid, a complex compound is formed. The cobalt ion can form complexes with nitrite ions.

### Step 3: Determine the Product
The reaction can be represented as:
\[ \text{Cobalt salt} + \text{KNO}_2 + \text{CH}_3\text{COOH} \rightarrow \text{Potassium cobalt nitrite} + \text{by-products} \]

The yellow precipitate formed is actually a complex of cobalt with nitrite ions.

### Step 4: Identify the Yellow Precipitate
The yellow precipitate formed in this reaction is:
\[ \text{K}_3[\text{Co(NO}_2)_6] \]
This compound is called potassium cobalt nitrite.

### Step 5: Conclusion
Thus, the yellow precipitate formed from the reaction of cobalt salt with potassium nitrite and acetic acid is potassium cobalt nitrite, represented as:
\[ \text{K}_3[\text{Co(NO}_2)_6] \]