In the reaction sequence: `CrO_(2)Cl_(2)overset(NaOH) to A overset(dil. H_(2)SO_(4)) to B overset (NaOH) to C overset(AgNO_(3)) to D`
Identify `[A]` to `[D]`.

Explanation

To solve the given reaction sequence, we will identify the compounds A, B, C, and D step by step based on the reactions provided.

### Step 1: Identify Compound A
The first reaction is between `CrO2Cl2` and `NaOH`.

**Reaction:**
\[ \text{CrO}_2\text{Cl}_2 + 4 \text{NaOH} \rightarrow \text{Na}_2\text{CrO}_4 + 2 \text{NaCl} + 2 \text{H}_2\text{O} \]

From this reaction, we can see that when `CrO2Cl2` reacts with `NaOH`, it forms **Compound A** which is:
\[ \text{A} = \text{Na}_2\text{CrO}_4 \]

### Step 2: Identify Compound B
Next, we take the compound A (`Na2CrO4`) and react it with dilute `H2SO4`.

**Reaction:**
\[ \text{Na}_2\text{CrO}_4 + \text{H}_2\text{SO}_4 \rightarrow \text{Na}_2\text{Cr}_2\text{O}_7 + \text{Na}_2\text{SO}_4 + 2 \text{H}_2\text{O} \]

From this reaction, we can see that **Compound B** is:
\[ \text{B} = \text{Na}_2\text{Cr}_2\text{O}_7 \]

### Step 3: Identify Compound C
Now, we take the compound B (`Na2Cr2O7`) and react it again with `NaOH`.

**Reaction:**
\[ \text{Na}_2\text{Cr}_2\text{O}_7 + 2 \text{NaOH} \rightarrow 2 \text{Na}_2\text{CrO}_4 + \text{H}_2\text{O} \]

From this reaction, we can see that **Compound C** is:
\[ \text{C} = \text{Na}_2\text{CrO}_4 \]

### Step 4: Identify Compound D
Finally, we take the compound C (`Na2CrO4`) and react it with `AgNO3`.

**Reaction:**
\[ \text{Na}_2\text{CrO}_4 + 2 \text{AgNO}_3 \rightarrow \text{Ag}_2\text{CrO}_4 + 2 \text{NaNO}_3 \]

From this reaction, we can see that **Compound D** is:
\[ \text{D} = \text{Ag}_2\text{CrO}_4 \]

### Summary of Compounds
- **A** = Na2CrO4
- **B** = Na2Cr2O7
- **C** = Na2CrO4
- **D** = Ag2CrO4