On heating `K_(4)[Fe(CN)_(6)]` with conc. `H_(2)SO_(4)` gives the gas

Options

A. `SO_(2)`
B. `CO_(2)`
C. `CO`
D. `NO_(2)`

Explanation

To solve the problem of what gas is produced when heating \( K_4[Fe(CN)_6] \) with concentrated \( H_2SO_4 \), we can follow these steps:

### Step 1: Understand the Reactants
We have the complex compound \( K_4[Fe(CN)_6] \), which is potassium ferrocyanide. When it is heated with concentrated sulfuric acid (\( H_2SO_4 \)), it undergoes a decomposition reaction.

### Step 2: Write the Reaction
The reaction can be represented as follows:
\[ K_4[Fe(CN)_6] + H_2SO_4 \rightarrow K_2SO_4 + FeSO_4 + (NH_4)_2SO_4 + CO \]
In this reaction, potassium sulfate (\( K_2SO_4 \)), iron(II) sulfate (\( FeSO_4 \)), ammonium sulfate (\( (NH_4)_2SO_4 \)), and carbon monoxide (\( CO \)) are produced.

### Step 3: Identify the Gas Produced
From the balanced reaction, we can see that the gas produced is carbon monoxide (\( CO \)).

### Step 4: Conclusion
Thus, the gas produced when heating \( K_4[Fe(CN)_6] \) with concentrated \( H_2SO_4 \) is \( CO \).

### Final Answer
The gas produced is \( CO \) (carbon monoxide).

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