What does Boyles law state about pressure and volume at?

Figure shows an air pillow. When the boy puts his head on the pillow, the air in the pillow is compressed. The pressure of the air increases to support his head.
Boyle’s law gives the relationship between the pressure and the volume of a fixed mass of gas at constant temperature.
The relationship between the pressure and the volume of a gas can be explained using the kinetic theory of gases.

(a) When the volume of a gas is decreased, the number of molecules per unit volume increases. (b) The same number of molecules move in a smaller space as shown in Figure. (c) The molecules collide more frequently with the walls of the container.
(d) The increase in the rate of collision results in an increase in the pressure exerted by the gas.
Table of Contents Show
Boyle’s law states that for a fixed mass of gas, the pressure of the gas is inversely proportional to its volume when the temperature is kept constant.
The mathematical expression for Boyle’s law:

that is, PV = constant when the temperature is kept constant.
When the pressure changes from P1 to P2 the volume changes from V1 to V2.

The product of pressure and volume remains constant. Therefore, P1V1 = P2V2.
The equation for Boyle’s law is:

when temperature and mass are constant.
P1 = intial pressure P2 = final pressure
V1 = initial volume V2 = final volume
The relationship between the pressure and the volume can also be expressed with the graphs in Figure.

People also ask
What is the Charles Law?
What is the Pressure Law?

Experiment:

Inference: The pressure on a gas affects its volume.
Aim: To determine the relationship between the pressure and the volume of a fixed mass of gas at constant temperature.
Problem: What is the relationship between the pressure and the volume of a fixed mass of gas at constant temperature?
Hypothesis: The volume of a fixed mass of gas decreases when the pressure is increased.
Variables: (a) Manipulated variable: Pressure (b) Responding variable: Volume of the air (c) Fixed variables: The mass of the air in the syringe and the temperature

Apparatus: A set of Boyle’s law apparatus consisting of a graduated glass syringe, standard weights, Bourdon gauge, rubber tubing, retort stand

Method:

Boyle’s Law is a basic law in chemistry describing the behavior of a gas held at a constant temperature. The law, discovered by Robert A. Boyle in 1662, states that at a fixed temperature, the volume of gas is inversely proportional to the pressure exerted by the gas. In other words, when a gas is pumped into an enclosed space, it will shrink to fit into that space, but the pressure that gas puts on the container will increase.

Perhaps a more straightforward way is to say Boyle's law is the relationship between pressure and volume. Mathematically, Boyle’s law can be written as pV=k, where p is the pressure of the gas, V is the volume of the gas, and k is a constant.

An example of Boyle’s law in action can be seen in a balloon. Air is blown into the balloon; the pressure of that air pushes on the rubber, making the balloon expand. If one end of the balloon is squeezed, making the volume smaller, the pressure inside increased, making the un-squeezed part of the balloon expand out. There is a limit to how much the air/gas can be compressed, however, because eventually the pressure becomes so great that it causes the balloon to break.

In this tutorial, you will learn about the Boyle’s law formula, and how this equation can be used to determine relationships between changes in pressure and changes in volume in a given closed system.

Robert Boyle, sometimes called the “Father of Modern Chemistry” worked in the fields of physics and chemistry. In 1660, Boyle published The Spring and Weight of the Air in which he described different experiments he created using a vacuum pump which he designed.

In 1662, Boyle published version two of The Spring and Weight of the Air. This is were he described the inverse relationship between pressure and volume, now known as Boyle’s Law. Boyle’s Law states that pressure and volume are inversely proportional to each other. As the pressure increases the volume decreases, and as the pressure decreases the volume increases. He made these observations by using mercury in a J-tube, and then made measurements of the volume of the gas at pressures both lower and higher than standard atmospheric pressure.

Boyle expressed his results in a relationship that is known as Boyle’s law equation or Boyle’s law formula: P1V1 = P2V2 . This law assumes the temperature remains constant.

Topics Covered in Other Articles

Important Things to Consider

The gas law described in this article only applies to ideal gases, which you can read about on our article, The Ideal Gas Law.

Relationship Between Pressure and Volume

Consider a sample of gas in a 1-liter container. From our article, What is Pressure, we know that the pressure exerted on the container from the gas is the sum of the collisions of the particles, divided by the surface area of the container,

. We also know that the volume is related to the surface area, and if the volume decreases, the surface area will decrease as well.

From these two relations, we can see that as the volume decreases, the total pressure is going to increase. This leads us to Boyle’s law formula,

We can make a graph of this relationship as follows:

Change in Pressure and Volume

This proportionality can enable us to solve specific problems relating to the changes in pressure and volume in a closed system.

Consider, for example, a piston full of oxygen. From this proportionality, we know that if the piston is compressed, the pressure of the gas will increase.

Boyle’s Law Equation – Example Problem

Here is an example of how you can solve a Boyle’s Law problem.

An ideal gas exerts a pressure of 3 atm in a 2 L container. What will the pressure be if the volume of the container is changed to 1 L at constant temperature?

Solution:

You can read about how a student used Boyle’s original data to verify Boyle’s Law.