Question

Define Osmosis. How will you determine the molar mass of a non-volatile solute by elevation of boiling point?

Hint:

Boiling point elevation is directly proportional to the molality of the solution. Higher molality means a higher boiling point elevation. Ensure correct units for accurate calculations.

Answer 1

Step 1: Define Osmosis.
Osmosis is the movement of solvent molecules from a region of lower solute concentration to a region of higher solute concentration, through a semi-permeable membrane. This continues until equilibrium is reached.
Step 2: Molar Mass Determination by Boiling Point Elevation.
The relationship between the boiling point elevation (\(\Delta T_b\)) and molality (\(m\)) of a solution is given by: \[ \Delta T_b = K_b \cdot m \] Where: - \( \Delta T_b \) is the boiling point elevation, - \( K_b \) is the ebullioscopic constant of the solvent, - \( m \) is the molality of the solution. To calculate the molar mass, rearrange the formula to find: \[ \text{Molar Mass} = \frac{m_{\text{solvent}} \cdot \Delta T_b}{K_b \cdot n_{\text{solute}}} \]