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.0.1 M glucose
ii.1% urea solution
iii.0.1 M common salt
Increasing order of osmotic pressure

Options

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

Explanation

To determine the increasing order of osmotic pressure for the given solutions, we will use the formula for osmotic pressure (π):

\[ \pi = iCRT \]

Where:
- \( \pi \) = osmotic pressure
- \( i \) = van 't Hoff factor (number of particles the solute dissociates into)
- \( C \) = molarity of the solution
- \( R \) = universal gas constant (which remains constant for our comparison)

Now, let's analyze each solution step by step.

### Step 1: Calculate the osmotic pressure for 0.1 M glucose (i = 1)
- **Concentration (C)** = 0.1 M
- **van 't Hoff factor (i)** = 1 (since glucose does not dissociate)

Using the formula:
\[ \pi_{glucose} = i \cdot C \cdot R = 1 \cdot 0.1 \cdot R = 0.1R \]

### Step 2: Calculate the osmotic pressure for 1% urea solution
1. **Convert 1% urea solution to molarity**:
- 1% solution means 1 g of urea in 100 mL of solution.
- Molecular weight of urea (NH₂CONH₂) = 60 g/mol.
- Moles of urea = \( \frac{1 \text{ g}}{60 \text{ g/mol}} = \frac{1}{60} \text{ mol} \).
- Molarity (C) = \( \frac{1/60 \text{ mol}}{0.1 \text{ L}} = \frac{1}{6} \text{ M} \).

2. **van 't Hoff factor (i)** = 1 (since urea does not dissociate).

Using the formula:
\[ \pi_{urea} = i \cdot C \cdot R = 1 \cdot \frac{1}{6} \cdot R = \frac{1}{6}R \]

### Step 3: Calculate the osmotic pressure for 0.1 M common salt (NaCl)
- **Concentration (C)** = 0.1 M
- **van 't Hoff factor (i)** = 2 (since NaCl dissociates into Na⁺ and Cl⁻).

Using the formula:
\[ \pi_{NaCl} = i \cdot C \cdot R = 2 \cdot 0.1 \cdot R = 0.2R \]

### Step 4: Compare the osmotic pressures
Now we have:
1. \( \pi_{glucose} = 0.1R \)
2. \( \pi_{urea} = \frac{1}{6}R \approx 0.1667R \)
3. \( \pi_{NaCl} = 0.2R \)

### Step 5: Arrange in increasing order
- \( \pi_{glucose} = 0.1R \)
- \( \pi_{urea} \approx 0.1667R \)
- \( \pi_{NaCl} = 0.2R \)

Thus, the increasing order of osmotic pressure is:
\[ \text{0.1 M glucose} < \text{1% urea solution} < \text{0.1 M common salt} \]

### Final Answer:
**Increasing order of osmotic pressure:**
1. 0.1 M glucose
2. 1% urea solution
3. 0.1 M common salt