1. What is Relative Volatility?

Definition: Relative Volatility is a measure comparing the vapor pressures of the components in a liquid mixture of chemicals.

Purpose: This quantity is widely used in designing large industrial distillation processes.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \alpha \) — Relative Volatility
• \( P_{a}^{Sat} \) — Saturated Vapour Pressure of More Volatile Component (Pa)
• \( P_{b}^{Sat} \) — Saturated Vapour Pressure of Less Volatile Component (Pa)

Explanation: The ratio of the saturated vapor pressures of the more volatile component to the less volatile component.

3. Importance of Relative Volatility

Details: Relative volatility is crucial in distillation column design as it determines how easily components can be separated.

4. Using the Calculator

Tips: Enter the saturated vapor pressures for both components in Pascals. Both values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What does a relative volatility of 1 mean?
A: A value of 1 means the components have equal volatility and cannot be separated by distillation.

Q2: What's a typical range for relative volatility?
A: For effective distillation, values typically range from 1.2 to 5. Higher values indicate easier separation.

Q3: How does temperature affect relative volatility?
A: Relative volatility generally decreases with increasing temperature as vapor pressures converge.

Q4: Can relative volatility be less than 1?
A: No, by definition the more volatile component is in the numerator, so α ≥ 1.

Q5: How is this used in distillation column design?
A: Higher α values require fewer theoretical plates for separation, affecting column height and energy requirements.