Properties such as boiling point, freezing point, and vapour pressure of a pure solvent change when solute molecules are added to get homogenous solution. These are called colligative properties.
Anwer the following questions:
i.`0.001 m NaCl`
ii.0.001 m urea
iii.`0.001 m MgCl_(2)`
iv.`0.001 m CH_(3)COOH`
Increasing order of boiling points

Options

A. `(ii) lt (iv) lt (i) lt (iii)`
B. `(iv) lt (i) lt (ii) lt (iii)`
C. `(iii) lt (ii) lt (i) lt (iiv)`
D. `(i) lt (ii) lt (iii) lt (iv)`

Explanation

To determine the increasing order of boiling points for the given solutions, we need to consider the van 't Hoff factor (i) for each solute, which represents the number of particles the solute dissociates into when dissolved in a solvent. The boiling point elevation (ΔTb) is directly proportional to the product of the van 't Hoff factor (i) and the molality (m) of the solution.

### Step-by-Step Solution:

1. **Identify the van 't Hoff factor (i) for each solute:**
- For **NaCl**: It dissociates into 2 ions (Na⁺ and Cl⁻), so i = 2.
- For **Urea**: It does not dissociate in solution, so i = 1.
- For **MgCl₂**: It dissociates into 3 ions (Mg²⁺ and 2 Cl⁻), so i = 3.
- For **Acetic Acid (CH₃COOH)**: It partially dissociates, but for simplicity, we can approximate i to be around 1.5 (since it is a weak acid and does not fully dissociate).

2. **Calculate the effective molality (i * m) for each solution:**
- For **0.001 m NaCl**:
\[ i \cdot m = 2 \cdot 0.001 = 0.002 \]
- For **0.001 m Urea**:
\[ i \cdot m = 1 \cdot 0.001 = 0.001 \]
- For **0.001 m MgCl₂**:
\[ i \cdot m = 3 \cdot 0.001 = 0.003 \]
- For **0.001 m CH₃COOH**:
\[ i \cdot m \approx 1.5 \cdot 0.001 = 0.0015 \]

3. **Rank the solutions based on the effective molality (i * m):**
- Urea: 0.001
- Acetic Acid: 0.0015
- NaCl: 0.002
- MgCl₂: 0.003

4. **Determine the increasing order of boiling points:**
The boiling point elevation is greater for solutions with higher effective molality. Therefore, the increasing order of boiling points is:
\[ \text{Urea} < \text{Acetic Acid} < \text{NaCl} < \text{MgCl}_2 \]

### Final Answer:
The increasing order of boiling points is:
**0.001 m Urea < 0.001 m CH₃COOH < 0.001 m NaCl < 0.001 m MgCl₂**