Partial Pressure Calculator

With this partial pressure calculator, you can get the pressure that a certain individual gas applies on the walls of the container in which it is enclosed. 

What is Partial Pressure?

In Chemistry,

“Partial pressure is how much pressure an individual gas applies on walls of container they are enclosed within”

The law of partial pressure is also known as Dalton's law of partial pressure.

Partial Pressure Formula:

The basic formula for calculating partial pressure is as follows:

$$ \text{Partial Pressure} = \text{Total Pressure} * \text{Mole Fraction} $$

What is Mole Fraction?

The mole fraction is the proportion of moles of a specific gas in a mixture divided by the total number of moles in the entire mixture.

Mathematically mole fraction is denoted by “X” and calculated as:

$$ \text{Mole Fraction} = \frac{\text{ No. Of Moles Of Selected Gas}}{\text{No. Of Moles Of Entire Gas Mixture}} $$

Dalton's Law - Partial Pressures:

According to Dalton’s law of partial pressure, the total pressure exerted by each gas in the mixture of gases equals the pressure exerted by the gas when isolated.

The Dalton’s Law of partial pressure formula is,

$$ \text{Total Pressure} = P_{1}+ P_{2}+, …, +P_{N} $$

Here P represents the partial pressures of each gas component.

Ideal Gas Law - Partial Pressure:

The ideal gas law of partial pressure is defined as the relationship between the volume V,  pressure P,  and temperature T of a particular gas at low pressure and high temperature.

Henry's Law also known to be the perfect gas law can be calculated by a partial pressure calculator, The equation for this is as follows:

$$ P*V = n*R*T $$

Where:

• P = Partial pressure of the gas
• V = Volume of the gas
• n = No. of moles of the gas
• R = Universal gas constant (0.0821 Latm/molK)
• T = Temperature of the gas

Henry’s Law - Partial Pressure:

The partial pressure under Henry's law is the amount of pressure exerted by a specific gas when it is dissolved in a liquid, and it directly relates to the concentration of the gas in the liquid.

Formula:

To find the partial pressures of individual gases accurately, we can use two different methods which are as follows:

Method 1:

In the case of Henry’s Law of partial pressure equation of the first method, when the concentration of the solution is given:

$$ Pressure = K_{H1} * Concentration $$

In this equation:

• KH1 = Henry’s law constant in [liter * atm/mol]

Method 2:

When the mole fraction of the solute is given, the equation for partial pressure is:

$$ Pressure = K_{H2} * Mole Fraction $$

Where:

• KH2 = Henry’s law constant in [atm]

How to Calculate Partial Pressures?

In the following example, you will be clear on how to find partial pressure manually.

Example:

A mixture of hydrogen and oxygen exerts 5.6 atm of pressure on the container's walls. Suppose hydrogen alone exerts a partial pressure of approximately 5atm, then what will be the mole fraction of oxygen in the entire mixture?

The formula for total pressure is:

$$ \text{Total Pressure} = P_{H_{2}}+ P_{O_{2}} $$

Putting values in the equation:

$$ 5.6 = 5 + P_{O_{2}} $$

$$ P_{O_{2}} = 5.6 – 5 $$

$$ P_{O_{2}} = 0.6 $$

To calculate the mole fraction of oxygen here we have:

$$ X_{oxygen} = \frac{P_{oxygen}}{P_{total}} $$

$$ X_{oxygen} = \frac{0.6}{5.6} $$

$$ X_{oxygen} = 0.107 $$

Working of Partial Pressure Calculator:

Finding partial pressure is so simple with the help of an online partial pressure calculator. You can easily calculate the results by entering a couple of inputs which include:

What to do:

• First, select the method from the box “Choose Formula” through which you are going to calculate.
• Choose the parameter you want to calculate.
• Enter all the values into their respective fields.
• Press the Calculate button.

What you get:

• Partial pressure
• Volume
• Mole fraction
• Temperature
• Concentration
• Amount of moles

FAQs:

What happens when partial pressure increases?

When the partial pressure increases due to the addition of any of the gas reactants or products, the equilibrium position is altered to reduce its partial pressure. This is usually done by selecting the reaction where the moles of the gaseous component are decreased.

What are the real-world applications of partial pressure?

There are many applications of partial pressure such as:

Scuba Diving: Whenever you dive, it is always recommended to keep your oxygen partial pressure between 0.16 (16%) and 1.6 (160%). There is a risk of serious injury and death if you fall below or above this range.

Chemical reactions: The partial pressure of gases is used to regulate reaction rates in a variety of industrial processes, as it influences reaction rates and product yields.

References:

Wikipedia.org: Partial pressure, Dalton's law of partial pressures, Ideal gas mixtures, Henry's law and the solubility of gases, and Mole fraction

Libretexts.org: Dalton's Law (Law of Partial Pressures), Derivation, and Mole Ratio