Education

# How Do I Study Thermodynamics in Physics for IIT JEE?

Physics is the science that examines matter, its motion and behaviour, as well as the things that are associated with it. Both KTG and Thermodynamics are included in the Chemistry and Physics curricula. It is also the scoring chapter, since every year two questions of eight marks are asked, which is not insignificant when considering the weighting. Students must review all of the key ideas and formulas in order to receive full points in this chapter. Thermodynamics covers a wide range of subjects, including the first law of thermodynamics, the adiabatic process, the isothermal process, the efficiency of the Carnot engine, and so on. We’ve included brief notes on the key subjects of KTG and Thermodynamics, as well as solved example questions, tips to remember, and more.

The Kinetic Theory of Gases

The Kinetic Theory of Gases is a theory that describes how gases move. Kinetic energy is the energy that is possessed by atoms or molecules as a result of their motion.

Kinetic Theory of Matter

Solids are defined as matter with a defined shape and volume. The attraction between any two solid molecules is quite strong. Liquids are defined as matter with a definite volume but no fixed form. The attraction between two molecules is not as strong as it is between solids. Gases are a type of matter that has no set shape or volume. Ideal Gas: An ideal gas has a molecular size of zero and a force of contact between its molecules of zero. Equation for Ideal gas: PV/T = Constant or PV = nRT. Number of moles here is n, while the universal gas constant is R.

Gas Constant

Universal gas constant (R). R= P0 V0/T0 = 8.311 J mol-1K-1.

Specific gas constant (r). PV= (R/M) T = rT. Here, r = R/M.

Real Gas: The gases that deviate from ideal gas behaviour are referred to as real gas. The number of carbon atoms present in 12 gramme of carbon-12 is known as Avogadro’s number (N). N = 6.023×1023.

What is Boyle’s law?

This rule says that if the temperature is maintained constant, the volume of a given amount of gas changes inversely with its pressure. PV = Constant Value.

What is Gey Lussac’s Law?

Gey Lussac’s law or Charler’s law: It says that if the pressure of a gas is held constant, the volume of a given amount of gas varies directly with its absolute temperature. Constant = V/T.

Degree of Freedom (n)

The number of independent ways that the system’s location and configuration can vary. In general, if N is the number of unconnected particles in a system, the degrees of freedom n of that system will equal n = 3N. The degree of freedom n of the system will be n = 3N –K if K is the number of constraints (restrictions).

Law of Energy Equipartition

In thermal equilibrium, all energy is shared evenly among all degrees of freedom in any dynamical system, and energy per molecule per degree of freedom equals 12 kT.  E = 12 kT.

Keep In Mind the Following

• In a genuine gas, we assume that the molecules are limited in size and that intermolecular attraction exists.
• At high temperatures and low pressures, real gases behave like ideal gases
• Vapours are the gaseous condition of stuff below the critical temperature. Gas is vapour below critical temperature and gas above critical temperature.
• A perfect gas’s internal energy is made up entirely of the kinetic energy of its molecules.

What is the definition of Thermodynamics?

It is the field of physics that deals with heat, work, and internal energy processes. Thermodynamics is concerned with the system’s macroscopic rather than microscopic behaviour. Everything outside of the system is referred to as the environment. Boundary refers to the physical or figurative surface that separates the system from its surroundings. It might be moveable or immovable.

Basic Terminology

• System: An area of the cosmos that is being studied.
• Open system: A system that can interchange both energy and matter with its environment is known as an open system. A permeable barrier is one that enables matter to pass across it. For instance, a water heater, a turbine, a vehicle radiator, the ocean, and so on. When analysing an open system, the energy entering the system is always equal to the energy leaving it.
• Closed System (m=constant): A system that allows energy but not mass to enter across its border. A greenhouse, for example, is a closed system that transfers heat but is not connected to its surroundings. A system transfers heat, work, or both depending on the characteristics of its border. An adiabatic border prevents the exchange of work between the environment and the system.
• Isolated system: A system that can’t interchange energy or matter with the rest of the world. An insulated gas cylinder, for example, or an insulated container.
• Surroundings: A part of the universe that interacts with the system but is not the system itself.
• Anything that divides the system from its surroundings is referred to as a boundary.