Ideal Gas Density Calculator
Calculate gas density using ideal gas law with pressure, temperature, and gas properties
Ideal Gas Density Calculator
Note: Use absolute pressure, not gauge pressure
R = R̄/M where R̄ = 8.314 J/(mol·K) and M is molar mass
Gas Density Results
Method:
Temperature: 0.00 K
Pressure: 0 Pa
Formula Used
ρ = P / (R × T)
Where ρ = density, P = pressure, R = specific gas constant, T = temperature
Example: Air Density at Standard Conditions
Given Conditions
Gas: Air
Temperature: 15°C = 288.15 K
Pressure: 101,325 Pa (1 atm)
Specific gas constant for air: 287 J/(kg·K)
Calculation
ρ = P / (R × T)
ρ = 101,325 Pa / (287 J/(kg·K) × 288.15 K)
ρ = 101,325 / 82,699
ρ = 1.225 kg/m³
Common Gas Properties
Air
Formula: N₂+O₂
M: 28.97 g/mol
R: 287 J/(kg·K)
Hydrogen
Formula: H₂
M: 2.016 g/mol
R: 4124 J/(kg·K)
Helium
Formula: He
M: 4.003 g/mol
R: 2077 J/(kg·K)
Nitrogen
Formula: N₂
M: 28.014 g/mol
R: 296.8 J/(kg·K)
Oxygen
Formula: O₂
M: 31.999 g/mol
R: 259.8 J/(kg·K)
Carbon Dioxide
Formula: CO₂
M: 44.01 g/mol
R: 188.9 J/(kg·K)
Ideal Gas Validity
High temperature (T >> Tcritical)
Low pressure (P << Pcritical)
Avoid near critical point
High pressure + low temperature
Calculation Tips
Always use absolute pressure (not gauge)
Temperature must be in Kelvin for calculations
Check compressibility factor for accuracy
Consider real gas effects at high pressure
Understanding Ideal Gas Density
What is Ideal Gas Density?
Ideal gas density is the mass per unit volume of a gas under the assumption that it behaves as an ideal gas. This assumes gas molecules have no volume and no intermolecular forces, which is approximately true at high temperatures and low pressures.
Key Principles
- •Density inversely proportional to temperature
- •Density directly proportional to pressure
- •Different gases have different densities
- •Real gases deviate from ideal behavior
Calculation Methods
Method 1: Specific Gas Constant
ρ = P/(R×T)
Use when you know the gas constant
Method 2: Molar Mass
ρ = (M×P)/(R̄×T)
Use when you know molecular weight
Relationship
R = R̄/M
Both methods are equivalent
Limitations of Ideal Gas Law
High Pressure
Molecular volume becomes significant, density higher than predicted
Low Temperature
Intermolecular forces become important, affects behavior
Near Critical Point
Large deviations, use equations of state instead
Practical Applications
Engineering Applications
- • HVAC system design
- • Pneumatic system calculations
- • Gas pipeline design
- • Combustion air calculations
Scientific Applications
- • Atmospheric studies
- • Gas chromatography
- • Chemical process design
- • Environmental monitoring