Vapor Pressure, Characteristics, Raoult՚s Law, Boiling Point, the Heat of Vaporization (For CBSE, ICSE, IAS, NET, NRA 2022)

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What is Vapor Pressure?


A liquid՚s vapor pressure is a vapor՚s equilibrium pressure above its liquid (or solid) ; that is, the vapor pressure resulting from a liquid (or solid) evaporation above a liquid (or solid) sample in a closed container.

What is Raoult՚s Law Equation?


Raoult՚s law is a chemical law that relates the solution՚s vapor pressure to the mole fraction of a solution added. The law of Raoult is expressed through the formula. .

Is Vapor Pressure Proportional to Temperature?


  • When a liquid՚s vapor pressure is the same as the atmospheric pressure, the material is at temperature and pressure at the boiling/freezing point.
  • Vapor stress depends on temperature. Raoult՚s law states that the solution՚s vapor pressure is directly proportional to the solvent՚s mole fraction.

Does Vapor Pressure Increase with a Boiling Point?


As a result, there are lower boiling points of liquids with high vapor pressure. By heating a liquid and allowing more molecules to enter the atmosphere, vapor pressure may be increased. This begins at the point where the vapor pressure is equal to the boiling atmospheric pressure.

Which Has Maximum Vapour Pressure?


  • The material with the lowest boiling point would, therefore, have the highest vapor pressure at room temperature (the easiest way to reach the gas phase) .
  • The highest boiling point material will have the lowest vapor pressure. Vapor pressure is an evaporation-related fluid element.

What is Vapor Pressure and What Causes It?


  • When a liquid is heated, its molecules obtain sufficient kinetic energy to overcome the forces holding them in the liquid and they escape into the gaseous phase.
  • By doing so, they generate a population of molecules in the vapor phase above the liquid that produces a pressure — the vapor pressure of the liquid.

What is the Importance of Vapour Pressure?


  • Vapor pressure, relating to boiling point and heat of vaporization, is the most important characteristic in the application of fats to fried food preparation.
  • Triglycerides have extremely low vapor pressures, so evaporation does not occur.

What Does High Vapor Pressure Mean?


  • Vapor pressure is a measure of the pressure exerted by a gas above a liquid in a sealed container. Strong intermolecular forces produce a lower rate of evaporation and a lower vapor pressure.
  • Weak intermolecular forces produce a higher rate of evaporation and a higher vapor pressure.

Why Does the Vapour Pressure Decrease when We Add a Non-Volatile Solute in the Solvent?


  • We know that evaporation is a surface phenomenon. The greater the surface area, the more is the evaporation. Hence, the vapour pressure is more.
  • In a pure liquid, we can see that there is more surface area available for the molecules to get evaporated. Therefore, they have more vapour pressure.

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