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 compounds A to G based on the given information and the reactions described.

### Step 1: Identify Compound A
Compound A has the molecular formula \( C_8H_8O \). A common compound fitting this formula is **acetophenone** (C6H5C(O)CH3), which has a phenyl group attached to a carbonyl group.

### Step 2: Reaction with Hydroxylamine
When compound A (acetophenone) reacts with hydroxylamine hydrochloride (\( NH_2OH.HCl \)), it forms oximes (B and C). The oxime formation involves the nucleophilic attack of hydroxylamine on the carbonyl carbon, leading to the formation of two geometric isomers:
- **B**: (E)-acetophenone oxime
- **C**: (Z)-acetophenone oxime

### Step 3: Rearrangement to Compounds D and E
Both oximes (B and C) can rearrange upon treatment with acid to yield:
- **D**: An isomer of B (possibly an amide)
- **E**: An isomer of C (possibly another amide)

### Step 4: Identify Compounds D and E
Since B and C are isomers of the formula \( C_8H_9NO \), D and E must also be isomers of this formula. They could be:
- **D**: Acetanilide (C6H5C(O)NH2)
- **E**: Another isomer such as N-phenylacetamide.

### Step 5: Reaction of D with Alcoholic KOH
When compound D (acetanilide) is boiled with alcoholic KOH, it undergoes dehydrohalogenation to form an oil:
- **F**: Aniline derivative (C6H7N).

### Step 6: Reaction of F with Acetyl Chloride
The oil (F) reacts rapidly with acetyl chloride (\( CH_3COCl \)) to regenerate compound D (acetanilide).

### Step 7: Reaction of E with Alkali and Acidification
On the other hand, compound E (N-phenylacetamide) when boiled with alkali followed by acidification yields a white solid:
- **G**: Benzoic acid (C7H6O2).

### Summary of Compounds
- **A**: Acetophenone (C6H5C(O)CH3)
- **B**: (E)-acetophenone oxime
- **C**: (Z)-acetophenone oxime
- **D**: Acetanilide (C6H5C(O)NH2)
- **E**: N-phenylacetamide
- **F**: Aniline derivative (C6H7N)
- **G**: Benzoic acid (C7H6O2)