A carbony compound of formula `C_(9) H_(10) O(A)`, which is a benzene derivative gives orange precipitate with 2,4-D.N.P. and also gives yellow precipitate with `I_(2)` in presence of aqueous NaOH. The total no. of isomers possible for 'A' are `"_____________"`

Answer

To solve the problem, we need to identify the possible isomers of the carbonyl compound with the formula C9H10O, which is a benzene derivative. The compound gives an orange precipitate with 2,4-Dinitrophenylhydrazine (2,4-DNP) and a yellow precipitate with iodine in the presence of aqueous NaOH, indicating it contains a carbonyl group and is likely to have a methyl ketone structure.

### Step-by-Step Solution:

1. **Identify the Functional Group**:
- The compound is a carbonyl compound (C=O) since it gives a positive test with 2,4-DNP.
- The yellow precipitate with iodine in NaOH indicates the presence of a methyl ketone (C=O with a CH3 group).

2. **Determine the Structure**:
- The molecular formula is C9H10O.
- Since we need a ketone (due to the haloform test), the structure must include a -COCH3 group.

3. **Count the Carbons**:
- The base structure of benzene has 6 carbons.
- We need to add 3 more carbons to the structure, which can be done in various ways.

4. **Identify Possible Isomers**:
- **Isomer 1**: Place the -COCH3 group at the para position of the benzene ring and add a propyl group (C3H7) at the ortho position.
- **Isomer 2**: Place the -COCH3 group at the ortho position and add an ethyl group (C2H5) at the meta position.
- **Isomer 3**: Place the -COCH3 group at the meta position and add an isopropyl group (C3H7) at the para position.
- **Isomer 4**: An aliphatic structure where the carbonyl group is not directly attached to the benzene ring, such as phenyl with a -CH2COCH3 group.

5. **Verify the Isomers**:
- Each of these structures must satisfy the molecular formula C9H10O and must be able to give the required tests (2,4-DNP and haloform test).

6. **Count the Total Isomers**:
- After analyzing the structures, we find that there are a total of 4 distinct isomers possible for the compound A.

### Final Answer:
The total number of isomers possible for 'A' is **4**.