1. What is the Ideal Gas Law?

The ideal gas law relates the pressure, volume, temperature, and amount of an ideal gas. The density form of this law allows calculation of gas density from molecular weight, pressure, and temperature.

2. How Does the Calculator Work?

The calculator uses the density form of the ideal gas law:

Where:

• \( \rho \) — Density (kg/m³)
• \( P \) — Pressure (Pascals)
• \( M \) — Molecular weight (kg/mol)
• \( R \) — Universal gas constant (8.314 J/mol·K)
• \( T \) — Temperature (Kelvin)

Explanation: The equation shows that gas density is directly proportional to pressure and molecular weight, and inversely proportional to temperature.

3. Importance of Density Calculation

Details: Calculating gas density is essential for many engineering applications, including fluid dynamics, process design, and equipment sizing in chemical and mechanical engineering.

4. Using the Calculator

Tips: Enter pressure in Pascals, molecular weight in kg/mol, and temperature in Kelvin. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What are the limitations of the ideal gas law?
A: The ideal gas law assumes no intermolecular forces and negligible molecular volume. It works best for low pressures and high temperatures.

Q2: How do I convert molecular weight from g/mol to kg/mol?
A: Divide the value in g/mol by 1000 to get kg/mol (e.g., 28.97 g/mol = 0.02897 kg/mol).

Q3: What is the universal gas constant R?
A: R = 8.314 J/mol·K is the standard value used in SI units. Other values exist for different unit systems.

Q4: Can this be used for real gases?
A: For real gases at high pressures or low temperatures, more complex equations of state (like van der Waals) should be used.

Q5: How does temperature affect gas density?
A: As temperature increases (at constant pressure), gas density decreases because the same number of molecules occupy more volume.