Compound 'X' containing chlorine, on treatment with `NH_(3)` gives a solid 'Y' which is free from chlorine. (Y) analysed as `C=49.31%,H=9.59%` and `N=19.18%` and reacts with `Br_(2)` and caustic soda to give a basic compound (Z),(Z) reacts with `HNO_(2)` to give ethanol. Suggest structure of (X), (Y) and (Z).

Answer

To solve the problem step by step, we will analyze the information given and derive the structures of compounds X, Y, and Z.

### Step 1: Determine the empirical formula of compound Y
Given the percentage composition of compound Y:
- C = 49.31%
- H = 9.59%
- N = 19.18%
- To find the percentage of O, we subtract the sum of the percentages from 100:
- O = 100% - (49.31% + 9.59% + 19.18%) = 21.92%

Now, we will calculate the number of moles of each element:
- Moles of C = 49.31 g / 12 g/mol = 4.10 mol
- Moles of H = 9.59 g / 1 g/mol = 9.59 mol
- Moles of N = 19.18 g / 14 g/mol = 1.37 mol
- Moles of O = 21.92 g / 16 g/mol = 1.37 mol

Next, we divide each mole value by the smallest number of moles (1.37):
- C: 4.10 / 1.37 ≈ 3
- H: 9.59 / 1.37 ≈ 7
- N: 1.37 / 1.37 = 1
- O: 1.37 / 1.37 = 1

Thus, the empirical formula of compound Y is C3H7N1O1, which can be written as C3H7NO.

### Step 2: Identify compound Y
Since compound Y is free from chlorine and has an amide functional group, we can deduce that it is propanamide (C3H7NO).

### Step 3: Determine the structure of compound Z
Compound Y (propanamide) reacts with Br2 and caustic soda (NaOH) to form compound Z. This is a classic reaction known as the Hofmann degradation, which converts an amide to a primary amine with one less carbon atom.

The reaction will yield:
- Z = Ethylamine (C2H5NH2)

### Step 4: Identify compound X
Compound X contains chlorine and reacts with ammonia (NH3) to form compound Y (propanamide). The compound that fits this description is propanoyl chloride (C3H5ClO).

### Summary of Structures
- **Compound X**: Propanoyl chloride (C3H5ClO)
- Structure: CH3CH2C(=O)Cl
- **Compound Y**: Propanamide (C3H7NO)
- Structure: CH3CH2C(=O)NH2
- **Compound Z**: Ethylamine (C2H5NH2)
- Structure: CH3CH2NH2