Difference Between Real Gas And Ideal Gas

What Is An Ideal Gas?

An ideal gas is a hypothetical gas whose molecules exhibit no intermolecular attractive forces and undergo elastic collision with each other and with the walls of the container. An ideal gas conforms to a particular idealized relation between pressure, volume and temperature referred to as ideal gas law. The ideal gas law assumes that all gases behave perfectly and identically to the rules of the kinetic molecular theory.

All gases are modeled on the assumption put forth by the Kinetic Theory of Matter, which assumes that all matter is made up of particles (i.e atoms or molecules); there are spaces between these particles and attractive forces become stronger as the particles converge. Particles are in constant, random motion, and they collide with one another and the walls of the container in which they are enclosed. Each particle has an inherent kinetic energy that is dependent upon temperature only.

A gas is considered ideal if its particles are so far apart that they do not exert any attractive forces upon one another. In real life, there is no such thing as a truly ideal gas, but at high temperatures and low pressures (conditions in which individual particles will be moving very quickly and be very far apart from one another so that their interaction is almost zero).

Properties Of Ideal Gas

  • An ideal gas is a hypothetical gas that does not really exist in the environment. Alternatively, an ideal gas can be described as a gas that meets all the assumptions of the kinetic molecular theory.
  • Ideal gases obey all gas laws under all conditions of temperature and pressure.
  • The volume occupied by the molecules is negligible as compared to the total volume occupied by the gas. In other words, the particles do not have a definite volume and mass.
  • Intermolecular attraction forces are not present between molecules.
  • Particles of ideal gas have elastic collision between molecules.
  • It obeys ideal gas equation PV=nRT.
  • An ideal gas may behave like a real gas at high pressure and low temperature conditions.
  • The ideal gas law assumes that all gases behave perfectly and identically to the rules of the kinetic molecular theory.

What Is A Real Gas?

A real gas also referred to as nonideal gas is gaseous compounds whose molecules occupy space, have interactions with intermolecular attraction forces present between the molecules of the gas. The volume occupied by the molecule is not negligible as compared to the total volume of the gas. In other words, the particles have a definite volume and mass. Consequently, real gases do not adhere to the ideal gas law. They only obey the ideal gas law if pressure is low or temperature is high.

Any gas that exists is a real gas. Examples of real gas include: Nitrogen, Oxygen, Hydrogen, Carbon Dioxide and Helium. Real gases can turn into liquids and solids at low temperatures and high pressure.

Properties Of  Real Gas

  • A real gas is a gaseous compound that really exists in the environment.
  • Real gases obey gas laws only at low pressures and high temperature.
  • The volume occupied by the molecule is not negligible as compared to the total volume of the gas. In other words, the particles have a definite volume and mass.
  • Intermolecular attraction forces are present between the molecules of the gas.
  • Particles of real gas have non-elastic collisions between molecules.
  • It obeys Van der waals equation (P +an2/V2 ) (v-nb)=nRT.
  • A real gas may behave as an ideal gas at low pressure and high temperature conditions.
  • Real gases can turn into liquids and solids at low temperatures and high pressure.
  • Examples of real gas include: Nitrogen, Oxygen, Hydrogen, Carbon Dioxide and Helium.

Difference Between Real Gas And Ideal Gas In Tabular Form

BASIS OF COMPARISON REAL GAS IDEAL GAS
Description A real gas is a gaseous compound that really exists in the environment.   An ideal gas is a hypothetical gas that does not really exist in the environment.
Gas Laws Real gases obey gas laws only at low pressures and high temperature.   Ideal gases obey all gas laws under all conditions of temperature and pressure.  
Volume The volume occupied by the molecule is not negligible as compared to the total volume of the gas. The volume occupied by the molecules is negligible as compared to the total volume occupied by the gas.
Intermolecular Attraction Forces Intermolecular attraction forces are present between the molecules of the gas.   Intermolecular attraction forces are not present between molecules.  
Collisions Of Particles Particles of real gas have non-elastic collisions between molecules.   Particles of ideal gas have elastic collision between molecules.  
Equation It obeys Van der waals equation (P +an2/V2 ) (v-nb)=nRT.   It obeys ideal gas equation PV=nRT.  
Behavior A real gas may behave as an ideal gas at low pressure and high temperature conditions.   An ideal gas may behave like a real gas at high pressure and low temperature conditions.  
Temperature & Pressure Real gases can turn into liquids and solids at low temperatures and high pressure.   The ideal gas law assumes that all gases behave perfectly and identically to the rules of the kinetic molecular theory.