1. What is Ratio of Partial Vapour Pressures?

Definition: This calculator determines the ratio of partial vapour pressures of water to another immiscible liquid in a mixture.

Purpose: It helps chemists and engineers understand the relative volatility of components in immiscible liquid mixtures.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_{W:B} \) — Ratio of partial pressures of water to liquid B
• \( W_{water} \) — Weight of water in the mixture (kg)
• \( M_B \) — Molecular mass of liquid B (kg)
• \( M_{water} \) — Molecular mass of water (0.018 kg)
• \( W_B \) — Weight of liquid B in the mixture (kg)

Explanation: The formula relates the weights and molecular masses of the components to their partial vapour pressures in the mixture.

3. Importance of Partial Pressure Ratio

Details: This ratio is crucial for distillation processes, understanding phase equilibria, and predicting component behavior in immiscible liquid systems.

4. Using the Calculator

Tips: Enter the weights of water and liquid B, their molecular masses (default for water is 0.018 kg). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What does a ratio > 1 indicate?
A: A ratio > 1 means water has higher partial pressure (more volatile) than liquid B in the mixture.

Q2: Why is molecular mass of water fixed at 0.018 kg?
A: 0.018 kg is the standard molecular mass of water (18 g/mol converted to kg).

Q3: Can this be used for miscible liquids?
A: No, this formula specifically applies to immiscible liquid mixtures.

Q4: How accurate is this calculation?
A: It provides theoretical values; actual ratios may vary with temperature and impurities.

Q5: What units should I use?
A: Use consistent units (kg for both weights and molecular masses) for accurate results.