An aliphatic hydrocarbon (A) of molecular weight 58 yields on chlorination a monochloroderivative (B) which on treatment with aqueous alkali gives an alcohol (C). The alcohol shows positive Lucas test immediately and easily dehydrated to form the compound (D) which on ozonolysis yields a ketone (E) as one of the products. Dry distillation of the calcium acetate as well as heating of two molecules of acetic acid with MnO at 250°C also gives the same ketone (E). Identity compounds (A) to (E) and explain the reactions.

Explanation

To solve the problem step by step, we will identify the compounds A to E and explain the reactions involved.

### Step 1: Identify Compound A
We start with an aliphatic hydrocarbon (A) with a molecular weight of 58. The simplest hydrocarbons that fit this molecular weight are alkanes.

- The molecular formula for alkanes is CnH(2n+2).
- For C4H10 (butane), the molecular weight is 58 (4*12 + 10*1 = 48 + 10 = 58).
- Therefore, compound A is **butane (C4H10)**.
...