Formula To Calculate Partial Vapour Pressure

Partial Vapor Pressure Formula:

\[ P_{vap_i} = y_i \times P_{total} \]

Partial Vapor Pressure (P_vap_i):

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1. What Is The Partial Vapor Pressure Formula?

The partial vapor pressure formula calculates the pressure exerted by a single component in a gas mixture. It follows Raoult's law for ideal mixtures and is fundamental in thermodynamics and chemical engineering applications.

2. How Does The Calculator Work?

The calculator uses the partial vapor pressure formula:

\[ P_{vap_i} = y_i \times P_{total} \]

Where:

\( P_{vap_i} \) — Partial vapor pressure of component i (Pa)
\( y_i \) — Mole fraction of component i (dimensionless)
\( P_{total} \) — Total pressure of the system (Pa)

Explanation: The partial pressure of a gas in a mixture is proportional to its mole fraction when the total pressure is known.

3. Importance Of Partial Pressure Calculation

Details: Calculating partial pressures is essential for understanding gas behavior in mixtures, predicting phase equilibria, designing separation processes, and modeling atmospheric phenomena.

4. Using The Calculator

Tips: Enter the mole fraction (between 0 and 1) and total pressure in pascals. Both values must be valid positive numbers with mole fraction not exceeding 1.

5. Frequently Asked Questions (FAQ)

Q1: What is mole fraction?
A: Mole fraction is the ratio of the number of moles of a component to the total number of moles in a mixture. It is a dimensionless quantity between 0 and 1.

Q2: Does this formula work for non-ideal mixtures?
A: This simple formula applies to ideal gas mixtures. For non-ideal mixtures, activity coefficients or more complex equations of state may be needed.

Q3: What units should I use for pressure?
A: While pascals (Pa) are the SI unit, you can use any pressure unit as long as you're consistent. The calculator defaults to pascals.

Q4: Can I calculate mole fraction from partial pressure?
A: Yes, you can rearrange the formula: \( y_i = \frac{P_{vap_i}}{P_{total}} \).

Q5: How does temperature affect partial vapor pressure?
A: Temperature affects the vapor pressure of pure components, which in turn affects partial pressures in mixtures. This simple formula assumes constant temperature.