Gas Pressure Formula: Pressure is defined as the force exerted by a substance on another substance per unit area. In the context of gases, gas pressure specifically refers to the force exerted by gas molecules on the boundaries of their container. These gas molecules exhibit random motion within a given volume, resulting in frequent collisions with both the container’s surface and each other. Although the impact of an individual gas molecule is minuscule and challenging to observe, the cumulative effect of all gas molecules collectively constitutes the overall gas pressure. It follows that the more collisions occurring, the higher the pressure will be.

The formula for gas pressure can be expressed as follows:

Where:

F represents the impact force due to gas collisions in Newtons (N), and

A denotes the area in square metres (m²).

Additionally, an ideal gas pressure formula is applicable, which relates pressure to other gas properties:

Where:

n is the number of moles,

R is the gas constant (8.3145 J/mol/K),

T is the temperature in Kelvin (K), and

V stands for volume.

The standard unit for measuring gas pressure in the International System of Units (SI) is the Pascal (Pa).

**Also Check – Theoretical Yield Formula**

**Gas Pressure Formula Solved Example**

**Example 1: **How do you determine the gas pressure when you have 500 moles of gas molecules in a container with a volume of 40 L, and the temperature is 220 K?

P= nRT / V

Substituting the given values:

n=500 mol,

T=220 K,

V=40 L.

Thus, the gas pressure (P) is calculated as:

P= 500×8.3145×220 / 40 = 225.5 Pascals (Pa)

P=225.5Pascals (Pa)

**Also Check – Vapor Pressure Formula**

**Example 2: **How can you calculate gas pressure when gas molecules apply a force of 300 N on an area of 50 m², using the basic pressure formula?

P= F / A

Substituting the provided values:

F=300 N,

A=50 m².

Thus, the gas pressure ( P) is calculated as:

P = 300 / 50 = 6 Pascals (Pa)

P= 6 Pascals (Pa)

**Also Check – Dilution Formula**

**Example 3:** Calculate the gas pressure when you have 2 moles of gas in a container with a volume of 10 liters at a temperature of 300 Kelvin.

Using the ideal gas pressure formula:

P = nRT / V

Substituting the given values:

n = 2 mol,

T = 300 K,

V = 10 L.

P = (2 × 8.3145 × 300) / 10 = 498.87 Pascals (Pa)

P = 498.87 Pascals (Pa)

**Example 4: **Determine the gas pressure when you have a container with 0.5 moles of gas at 25 degrees Celsius (298 Kelvin) and a volume of 2 liters.

Using the ideal gas pressure formula:

P = nRT / V

Substituting the given values:

n = 0.5 mol,

T = 298 K,

V = 2 L.

P = (0.5 × 8.3145 × 298) / 2 = 623.29 Pascals (Pa)

P = 623.29 Pascals (Pa)

**Example 5:** Calculate the gas pressure when 4 moles of gas molecules exert a force of 800 Newtons on an area of 100 square meters.

Using the basic pressure formula:

Substituting the provided values:

F = 800 N,

A = 100 m².

P = 800 / 100 = 8 Pascals (Pa)

P = 8 Pascals (Pa)

**Example 6:** Calculate the gas pressure inside a sealed container with 3 moles of gas at a temperature of 350 Kelvin and a volume of 8 liters.

Using the ideal gas pressure formula:

Substituting the given values:

n = 3 mol,

T = 350 K,

V = 8 L.

P = (3 × 8.3145 × 350) / 8 = 1089.1 Pascals (Pa)

P = 1089.1 Pascals (Pa)

These examples serve as practical demonstrations that showcase the application of the respective gas pressure formulas. By considering the provided variables and conditions, individuals can gain a clear understanding of how to calculate gas pressure in various scenarios.

## Gas Pressure Formula FAQs

### What is gas pressure?

Gas pressure arises from the impact of gas molecules on the inner walls of their enclosure, distributed over a specific surface area.

### How is gas pressure measured?

Gas pressure is typically measured in Pascals (Pa) or atmospheres (atm) using instruments like barometers or manometers.

### What is the ideal gas pressure formula?

The formula for ideal gas pressure is expressed as: P = nRT / V, with P representing pressure, n denoting the number of moles, R as the gas constant, T representing temperature in Kelvin, and V representing volume.

### What is the SI unit for pressure?

The Pascal (Pa) is the standard unit of measurement for pressure in the International System of Units (SI).

### How does temperature affect gas pressure?

With rising temperature, gas molecules gain greater kinetic energy, resulting in increased collision frequency and intensity, ultimately causing elevated gas pressure.