Fugacidade (aprox)

f ≈ P.
Created by
Renato Passos, Eng. de Software
Reviewed by
Renato Passos, Eng. de Software

Last updated: Apr 18, 2026

f (atm)
1,000

About this calculator

The fugacity of a gas is a measure of its tendency to expand or mix with other gases. It is an important thermodynamic property, especially in chemical and physical processes involving gases. The approximate fugacity calculator uses the formula f ≈ P, where f is the fugacity and P is the pressure of the gas. This approximation is valid for ideal gases or under conditions of low pressure and high temperature.

The formula f ≈ P is based on the definition of fugacity as a measure of the difference between the real and ideal behavior of a gas. Under conditions of low pressure and high temperature, gases behave almost ideally, making this approximation valid. However, under conditions of high pressure and low temperature, the fugacity can deviate significantly from the pressure, and more complex equations are needed to obtain accurate values.

Fugacity is an important property in many chemical and physical processes, such as ammonia synthesis, fuel production, and gas separation. It is also used to predict the stability of gas mixtures and the formation of condensates. The approximate fugacity calculator is a useful tool for estimating the fugacity of a gas under specific conditions, but it is essential to remember that it is an approximation and may not be accurate in all situations.

When using the approximate fugacity calculator, it is crucial to be careful with the units of pressure and temperature. The pressure should be expressed in absolute pressure units, such as pascal or atmosphere, and the temperature should be expressed in absolute temperature units, such as kelvin. Additionally, it is essential to verify if the conditions of low pressure and high temperature are met to ensure the validity of the approximation.

Frequently asked questions

What is fugacity?

Fugacity is a measure of a gas's tendency to expand or mix with other gases.

When to use the formula f ≈ P?

The formula f ≈ P is valid for ideal gases or under conditions of low pressure and high temperature.

What are the units of pressure and temperature to use in the calculator?

The pressure should be expressed in absolute pressure units, such as pascal or atmosphere, and the temperature should be expressed in absolute temperature units, such as kelvin.

Is fugacity important in chemical and physical processes?

Yes, fugacity is an important property in many chemical and physical processes, such as ammonia synthesis, fuel production, and gas separation.

Is the approximate fugacity calculator accurate in all situations?

No, the approximate fugacity calculator is an approximation and may not be accurate in all situations, especially under conditions of high pressure and low temperature.

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