1. What is Ostwald-Walker Dynamic Method?

Definition: This method measures the relative lowering of vapour pressure when a non-volatile solute is added to a solvent.

Purpose: It helps determine the effect of solutes on vapour pressure, which is important in colligative properties studies.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \Delta p \) — Relative Lowering of Vapour Pressure
• \( w_A \) — Loss of Mass in bulb set A (kg)
• \( w_B \) — Loss of Mass in bulb set B (kg)

Explanation: The mass loss in set B (containing solution) divided by the total mass loss gives the relative lowering of vapour pressure.

3. Importance of Vapour Pressure Lowering

Details: Vapour pressure lowering affects boiling point elevation, freezing point depression, and osmotic pressure - all important colligative properties.

4. Using the Calculator

Tips: Enter the mass loss from bulb set A (pure solvent) and bulb set B (solution). Both values must be ≥ 0 and their sum must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What do bulb sets A and B represent?
A: Set A contains pure solvent, while set B contains the solution being studied.

Q2: Why is this method called "dynamic"?
A: Because it involves a continuous flow of dry air through the system, creating dynamic equilibrium conditions.

Q3: What units should be used for mass measurements?
A: The calculator uses kilograms, but consistent units can be used as long as both measurements are in the same unit.

Q4: What does the result represent?
A: The result (Δp) represents the fraction by which the vapour pressure is lowered compared to the pure solvent.

Q5: Can this method be used for volatile solutes?
A: No, this method is specifically for non-volatile solutes. For volatile solutes, other methods must be used.