Compound (A) `(C_(8)H_(8)O)` on treatment with `NH_(2)OH.HCl` gives (B) and (C ). (B) and (C ) rearrange to give (D) and E, respectively, on treatment with acid. (B), (C ), (D), and (E ) are all isomers of molecular formula `(C_(8)H_(9)NO)`. When (D) is boiled with alcoholic KOH, an oil (F) `(C_(6)H_(7)N)` separates out. (F) reacts rapidly with `CH_(3)COCl` to give back (D). On the other hand, (E ) on boiling with alkali followed by acidification gives a white solid (G) `(C_(7)H_(6)O_(2))`. Identify (A) to (G).

Answer

To solve the problem step by step, we will identify the compounds A to G based on the information provided in the question and the video transcript.

### Step 1: Identify Compound A
- **Given**: Compound A has the molecular formula C8H8O.
- **Analysis**: The structure that fits this formula and is commonly known is methyl phenyl ketone, which is also known as acetophenone.
- **Conclusion**: **Compound A = Acetophenone (C6H5C(O)CH3)**

### Step 2: Reaction of A with NH2OH.HCl
- **Reaction**: Acetophenone reacts with hydroxylamine (NH2OH) in the presence of HCl to form oxime derivatives.
- **Products**: This reaction yields two isomers, which we will denote as B and C.
- **Conclusion**: **Compound B = Acetophenone oxime (C6H5C(NO)CH3)** and **Compound C = Another isomer of acetophenone oxime (C6H5C(NO)C2H5)**.

### Step 3: Rearrangement of B and C to form D and E
- **Process**: B and C undergo Beckmann rearrangement when treated with acid.
- **Products**: This rearrangement leads to the formation of two isomers, D and E.
- **Conclusion**: **Compound D = N-phenylacetamide (C6H5C(O)NHCH3)** and **Compound E = Another isomer (C6H5C(O)NH(C2H5))**.

### Step 4: Reaction of D with Alcoholic KOH
- **Reaction**: When Compound D is boiled with alcoholic KOH, it undergoes dehydrohalogenation or elimination to form an oil.
- **Product**: This product is an amine.
- **Conclusion**: **Compound F = Aniline derivative (C6H7N)**.

### Step 5: Reaction of F with CH3COCl
- **Reaction**: Compound F reacts rapidly with acetyl chloride (CH3COCl) to regenerate Compound D.
- **Conclusion**: This confirms that **Compound D = N-phenylacetamide (C6H5C(O)NHCH3)**.

### Step 6: Reaction of E with Alkali followed by Acidification
- **Process**: Compound E is treated with alkali followed by acidification.
- **Product**: This reaction results in a white solid.
- **Conclusion**: **Compound G = Benzoic acid (C7H6O2)**.

### Summary of Compounds
- **Compound A**: Acetophenone (C6H5C(O)CH3)
- **Compound B**: Acetophenone oxime (C6H5C(NO)CH3)
- **Compound C**: Another isomer of acetophenone oxime
- **Compound D**: N-phenylacetamide (C6H5C(O)NHCH3)
- **Compound E**: Another isomer of N-phenylacetamide
- **Compound F**: Aniline derivative (C6H7N)
- **Compound G**: Benzoic acid (C7H6O2)