Home Back

Rate of Effusion for First Gas given Densities by Graham's law Calculator

Graham's Law Formula:

\[ r_1 = \sqrt{\frac{d_2}{d_1}} \times r_2 \]

kg/m³
kg/m³
m³/s

Unit Converter ▲

Unit Converter ▼

From: To:

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:

\[ r_1 = \sqrt{\frac{d_2}{d_1}} \times r_2 \]

Where:

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.

Rate of Effusion Calculator by Graham's Law© - All Rights Reserved 2025