1. What is Graham's Law of Effusion?

Definition: Graham's Law states that the rate of effusion of a gas is inversely proportional to the square root of its molar mass (or density at constant temperature and pressure).

Purpose: This calculator helps determine the effusion rate of one gas relative to another when their densities are known.

2. How Does the Calculator Work?

The calculator uses Graham's Law formula:

Where:

• \( r_1 \) — Rate of effusion of first gas (m³/s)
• \( r_2 \) — Rate of effusion of second gas (m³/s)
• \( d_1 \) — Density of first gas (kg/m³)
• \( d_2 \) — Density of second gas (kg/m³)

Explanation: The ratio of effusion rates is inversely proportional to the square root of the ratio of their densities.

3. Importance of Graham's Law

Details: This law is fundamental in understanding gas behavior, separation of isotopes, and industrial gas processes.

4. Using the Calculator

Tips: Enter the densities of both gases (default values provided) and the effusion rate of the second gas. All density values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is effusion?
A: Effusion is the process where gas molecules escape through a tiny hole into a vacuum.

Q2: Why does Graham's Law depend on density?
A: At constant temperature and pressure, density is directly proportional to molar mass, which determines molecular speed.

Q3: What are typical gas densities?
A: Common gas densities at STP range from 0.09 kg/m³ (H₂) to 1.98 kg/m³ (CO₂).

Q4: Can I use molar mass instead of density?
A: Yes, since density ratio equals molar mass ratio at constant T and P.

Q5: What's the practical application of this calculation?
A: Used in gas separation processes, determining unknown molecular weights, and predicting gas behavior.