Behaviour of Gases – Class 11 | Chapter – 13 | Physics Short Notes Series PDF for NEET & JEE
Behaviour of Gases: The properties and laws obeyed by the molecules of the gas dictate the behavior of gas molecules. Physicists have encountered many differences among the molecular distribution of a gas and a liquid or a solid substance. To explain the tendency and the distribution of molecules in a gas, gas laws, and gas properties have been developed. The kinetic theory of gas molecules explains the behavior of gas molecules. We can study the gas molecules at a microscopic level.
Behaviour of Gases
- A gas is composed of the collaboration of a large number of molecules.
- The larger number of distances among the gas molecules make the volume of the gas almost negligible.
- There is a minor amount of intermolecular interactions found in gas.
- The collision of the gas molecules is elastic. It doesn’t matter if it is between themselves or with the wall of the container.
What is Gas in Science?
In science, gas is one of the three main states of matter, alongside solids and liquids. Gases are characterized by their low density, lack of fixed shape, and ability to expand to fill their container.
At the molecular level, gases consist of molecules that are free to move in any direction and at any speed within the container. These molecules collide with one another and with the walls of the container, creating pressure that is proportional to their number, temperature, and volume.
Gases also have some unique physical properties, such as compressibility and expansibility, which are a consequence of the weak intermolecular forces between the molecules. This means that gases can be compressed to occupy smaller volumes and can expand to fill larger volumes, depending on the pressure and temperature of the surroundings.
The behavior of gases can be described by a number of laws and principles, such as Boyle’s law, Charles’s law, Avogadro’s law, and the ideal gas law. These laws provide a quantitative understanding of the behavior of gases in different conditions and are used in many applications, such as in the design of gas storage and distribution systems, the calculation of gas densities and volumes, and the understanding of atmospheric phenomena such as weather and climate.
The table given below shows the properties of gases:
|Quantity of Gas||n||mol|
Behaviour of Gas Molecules
The behavior of gas molecules can be described in terms of their motion and interactions with one another and with their container. At the molecular level, gas molecules are in constant motion, moving in random directions and at high speeds. The behavior of gas molecules can be described using the kinetic theory of gases, which provides a model for understanding the macroscopic behavior of gases in terms of the motion of their constituent molecules.
One of the key properties of gas molecules is their kinetic energy, which is determined by their temperature. As the temperature of a gas increases, the average kinetic energy of its molecules increases, leading to faster and more energetic motion.
The behavior of gas molecules is also affected by the pressure and volume of the container in which they are contained. When the volume of a container is decreased, the gas molecules become more closely packed together, leading to more frequent collisions and a higher pressure. When the volume of a container is increased, the gas molecules become more spread out, leading to fewer collisions and a lower pressure.
Gas molecules also interact with one another through collisions, which can be elastic or inelastic depending on the energy of the colliding molecules. Elastic collisions involve a transfer of kinetic energy between the colliding molecules, while inelastic collisions involve a transfer of both kinetic and potential energy.
Overall, the behavior of gas molecules is complex and can be influenced by a wide range of factors, including temperature, pressure, volume, and the properties of the gas molecules themselves. The study of gas behavior is an important area of science with many practical applications, including the design of engines, the storage and distribution of gases, and the study of atmospheric phenomena.
What are Gases made of?
Gases are made up of individual molecules or atoms that are not bound together in a fixed structure. In other words, the particles that make up a gas are not arranged in a regular pattern, as they are in solids and liquids. Instead, gas particles move freely and independently, and are separated by empty space.
Most gases in the Earth’s atmosphere are made up of diatomic molecules, such as nitrogen (N2), oxygen (O2), and hydrogen (H2). These molecules consist of two atoms bonded together, and they are held together by strong covalent bonds.
Other gases in the atmosphere, such as carbon dioxide (CO2) and water vapor (H2O), are made up of three or more atoms, and are held together by weaker intermolecular forces.
In addition to these atmospheric gases, there are many other gases that can be found in nature or in industrial processes. These can include noble gases, such as helium and neon, which consist of individual atoms rather than molecules, as well as more complex molecules, such as methane (CH4), which is a key component of natural gas.
Overall, the specific composition of a gas depends on a wide range of factors, including its source, the temperature and pressure at which it is found, and the presence of other gases or chemicals in the environment.
What is Real Gas?
A real gas is a gas that does not obey the assumptions of the ideal gas law, which is a simplified model that assumes that gas molecules are point particles with zero volume and no intermolecular forces. In reality, gas molecules have finite volume and interact with one another through weak intermolecular forces, such as van der Waals forces.
At high temperatures and low pressures, most gases behave in a way that is consistent with the predictions of the ideal gas law. However, at low temperatures and high pressures, the behavior of gases becomes increasingly different from that predicted by the ideal gas law, and the effects of intermolecular forces become more significant.
What is Flue Gas?
Flue gas is a gas that exists in the atmosphere as a result of a flue. The flue gases are formed into the atmosphere due to the release of the gas from the furnace, oven, broiler, fireplace, etc. through a channel.
What is an Ideal Gas?
An ideal gas is a theoretical aspect. It is believed that an ideal gas is the composition of many randomly moving point particles. These particles undergo inter-particle interactions.
The formula for an ideal gas is the product of pressure and volume of a one-gram molecule of an ideal gas is the same as the product of a universal gas constant, absolute temperature, and the number of moles of the gas.
To know what is the ideal gas constant, the mathematical expression is:
PV = nRT = NkT
- P = Pressure of the gas
- V = Volume of the gas
- n = Number of moles
- R = Universal gas constant = 8.3145 J. mol-1. K-1
- T = Temperature of the gas
- N = Avogadro’s number (NA = 6.0221 × 1023)
What are the Ideal Gas Laws?
The ideal gas laws are a set of fundamental principles that describe the behavior of gases under a wide range of conditions. The three main ideal gas laws are:
- Boyle’s law: At a constant temperature, the volume of a gas is inversely proportional to its pressure. In other words, if the pressure on a gas is increased, its volume will decrease, and if the pressure is decreased, the volume will increase.
- Charles’s law: At a constant pressure, the volume of a gas is directly proportional to its temperature. In other words, if the temperature of a gas is increased, its volume will increase, and if the temperature is decreased, the volume will decrease.
- Gay-Lussac’s law: At a constant volume, the pressure of a gas is directly proportional to its temperature. In other words, if the temperature of a gas is increased, its pressure will increase, and if the temperature is decreased, the pressure will decrease.
These three laws can be combined into the ideal gas law, which relates the pressure (P), volume (V), temperature (T), and number of moles (n) of a gas:
PV = nRT
where R is the gas constant, which is a universal constant that depends on the units used to measure P, V, T, and n. This equation provides a way to predict the behavior of an ideal gas under different conditions.
It is important to note that the ideal gas laws apply only to ideal gases, which are hypothetical gases that obey all of the assumptions of the ideal gas model. In reality, most gases deviate to some degree from the ideal gas model, and the behavior of real gases must be described using more complex equations of state.
|JOIN OUR TELEGRAM CHANNELS|
|Biology Quiz & Notes||Physics Quiz & Notes||Chemistry Quiz & Notes|
By Team Learning Mantras