Boiling Point with Heat Of Vaporization: Detailed Analysis


In the present article, we are going to discuss regarding the boiling point with the heat of vaporization and its detailed analysis.

The quantity of heat needs to be added to any liquid if you intend to convert that liquid into gas. The symbol that represents the change in enthalpy of vaporization is ∆Hvap. The vaporization process occurring exactly at the boiling point is nothing but boiling.

The boiling point with heat of vaporization

It is experimentally found that at a specific point of temperature, we can have the vapor pressure possessing the same value as that of the atmospheric pressure that surrounds the liquid, and also, at this point, the liquid approaches the vapor state. The vaporization process occurring exactly at the boiling point is nothing but boiling.

The quantity of heat that requires to be added to any liquid if you are intending to convert that liquid into a gas is itself the heat of vaporization. The variation of boiling point with heat of vaporization is directly proportional.

 boiling point with heat of vaporization
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How to find the boiling point with heat of vaporization?

If we take one gram of any liquid to vaporize it at a constant temperature, we may need some amount of heat, and this required heat is usually termed as the heat of vaporization. We can find the boiling point with heat of vaporization by the clausius- clapeyron equation.

Similarly, the molar heat of vaporization corresponds to the required amount of heat in the case of one mole of a liquid, along with no variation in temperature.

How do you calculate the boiling point from vapor pressure?

At the critical point, the enthalpy of vaporization is found to approach zero. Until this point, the enthalpy of vaporization can be reduced by the influence of pressure, i.e., by increasing the pressure. Thus, a higher vapor pressure corresponds to a lower boiling point and vice versa. We can calculate the boiling point by Clausius- clapeyron equation given by,

ln(P2/P1)=−ΔHvapR⋅(1/T2−1/T1)

Where,

P1 – the vapor pressure of the substance at T1

P2 – the vapor pressure of that substance at T2

ΔHvap – the enthalpy of vaporization.

R – the gas constant – generally expressed as 8.314 J/K⋅mol.

We will not witness a phase change corresponding to the process of vaporization at the so-called critical point. Heat is necessary to overcome the molecular bonds, simply referred to as latent heat.

How do you calculate the boiling point of entropy of vaporization?

At standard pressure, the entropy of vaporization of most of the liquids would possess somewhat similar values. According to Trouton’s rule, most of the liquids possess an entropy of vaporization of about 85 to 88 J mol−1 K−1. It is found that the heat of vaporization divided by the boiling point of that liquid gives the heat of vaporization directly.

Is the heat of vaporization the same as the boiling point?

The vaporization process occurring exactly at the boiling point is nothing but boiling. It is experimentally found that at a specific point of temperature, we can have the vapor pressure possessing the same value as that of the atmospheric pressure that surrounds the liquid, and also, at this point, the liquid approaches the vapor state.

This point is also referred to as the vaporization point. The vaporization process occurring exactly at the boiling point is nothing but boiling.

How to find a boiling point from a vapor pressure graph?

In a vapor pressure curve, a line drawn from the point on the axis of pressure corresponding to the standard pressure cuts the curve at a point. This point, when extrapolated towards the temperature axis, it meets the axis at the boiling point. Thus, we can find the boiling point.

Name the factors that tend to influence boiling point with heat of vaporization?

We already learned that the process of vaporization occurring exactly at the boiling point is nothing but boiling so, we study the variation of boiling point with heat of vaporization. The factors that may affect the heat of vaporization are mentioned below,

  • Temperature if the substance is in the liquid phase
  • Number of moles present in a liquid phase
  • Vapor pressure when in evaporated phase

What do you mean by the heat of vaporization in chemistry?

If we take one gram of any liquid to vaporize it at a constant temperature, we may need some amount of heat, and this required heat is usually termed as the heat of vaporization. Similarly, the molar heat of vaporization corresponds to the required amount of heat in the case of one mole of a liquid, along with no variation in temperature.

How do you explain the boiling point with heat of vaporization?

Enthalpy of vaporization is the same as that of the heat of vaporization i.e.., the quantity of heat that need to be added to any liquid if you are intending to convert that liquid into gas. The symbol that represents the change in enthalpy of vaporization is ∆Hvap.

Is it possible for the heat of vaporization to be numerically negative?

It is assumed that the enthalpy of condensation or the heat of condensation is exactly the same (numerically) as that of the enthalpy of vaporization and only differs by the sign. It is necessary to mention that the enthalpy of vaporization is said to be always positive, whereas the changes in enthalpy of condensation are found to be negative.

What do you know about the boiling point temperature?

It is experimentally found that at a specific point of temperature, we can have the vapor pressure possessing the same value as that of the atmospheric pressure that surrounds the liquid, and also, at this point, the liquid approaches the vapor state. The vaporization process occurring exactly at the boiling point is nothing but boiling.

Is the boiling point with heat of vaporization important?

In order to transform water to the vapor state, we need to break the hydrogen bond that is known to be present in between the hydrogen and oxygen atoms that constitute the water. To break the bond, there is a requirement of a very high heat of vaporization this actually favors the possibility of life on earth.

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What factors take part in increasing the boiling point with heat of vaporization?

We are aware of the existence of four intermolecular forces, namely, ionic bonding, hydrogen bonding, dipole-dipole interaction, and van der Waals dispersion forces. These are all found to be the attraction forces that participate independently based on the existing functional group. By keeping on increasing the number of carbons attached, we can achieve an increase in boiling point.

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Name the liquid that is found to have the highest boiling point?

Acetone is observed to be having the highest possible boiling point with heat of vaporization which is 56.0 ∘C. This is possibly true due to the existence of more number of carbon atoms in the acetone.

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How much is boiling point with heat of vaporization in water?

Generally, the heat of vaporization corresponding to water is very high, which means that if we aim to transform one gram of water into a gas when there is no change in temperature, we would require a large quantity of heat. Therefore, the heat of vaporization is found to be approximately 540 cal/g while the temperature kept constant will be 100°C.

What do you mean by specific heat?

Specific heat is basically a parameter that measures heat. If we are supposed to increase the temperature of the substance taken in unit mass, we will need a particular quantity of heat. This necessary heat is nothing but the specific heat of that substance. There occurs a relation between the heat with temperature change which is responsible for water being used as a temperature regulator.

What is high specific heat meant to be?

If we are supposed to increase the temperature of the substance taken in unit mass, we will need a particular quantity of heat. This necessary heat is nothing but the specific heat of that substance. Water is observed to possess a high specific heat capacity or just the heat capacity, which infers that more heat must be provided in order to raise the temperature of water in comparison with the rest of the substances.

What does the symbol ‘∆H’ represent?

It is a symbol associated with thermodynamic properties that are found to be very useful. We are already aware of the symbol ‘H’ that corresponds to the enthalpy of the substance. Enthalpy is nothing but the total sum of the internal energy that is possessed by any system, along with the product of pressure and volume present in that system. Further, ∆H is associated with the variation or change observed in the enthalpy of the system in a chemical reaction.

What do you mean by a vaporization point?

It is experimentally found that at a specific point of temperature, we can have the vapor pressure possessing the same value as that of the atmospheric pressure that surrounds the liquid, and also, at this point, the liquid approaches the vapor state. This point is also referred to as the vaporization point. The vaporization process occurring exactly at the boiling point is nothing but boiling.

Explain whether the pressure of a liquid influences the boiling point with heat of vaporization?

Pressure is also a physical property associated with a substance. At the critical point, the enthalpy of vaporization is found to approach zero. Until this point, the enthalpy of vaporization can be reduced by the influence of pressure, i.e., by increasing the pressure. We will not witness a phase change corresponding to the process of vaporization at the so-called critical point. Heat is necessary to overcome the molecular bonds, which are simply referred to as latent heat.

What do you mean by the heat of the solution?

When the substance is added to a solvent, it is observed to be dissolved heat will be evolved or be absorbed. The quantity of heat that is believed to be evolved while one mole goes on to dissolve in a solvent is nothing but the heat of the solution.

What are some of the factors which can affect latent heat of vaporization?

 The vaporization is mainly influenced by the very well-known boiling point of a liquid. The means factors affecting vaporization mean factors affecting boiling point.

The factors which affect boiling point with heat of vaporization are listed here

  • pressure
  • Addition of impurities

What is the application associated with a vapor pressure curve?

   In a vapor pressure curve, a line drawn from the point on the axis of pressure corresponding to the standard pressure cuts the curve at a point. This point, when extrapolated towards the temperature axis, it meets the axis at the boiling point. Thus, we can find the boiling point with heat of vaporization.

Mention the Clausius Clapeyron equation

A higher vapor pressure corresponds to a lower boiling point and vice versa. We can calculate the boiling point with heat of vaporization by Clausius- clapeyron equation given by,

                                                            ln(P2/P1)=−ΔHvapR⋅(1/T2−1/T1)

Where,

P1 – the vapor pressure of the substance at T1

P2 – the vapor pressure of that substance at T2

ΔHvap – the enthalpy of vaporization.

R – the gas constant – generally expressed as 8.314 J/K⋅mol.

Summary

At the critical point, the enthalpy of vaporization is found to approach zero. Until this point, the enthalpy of vaporization can be reduced by the influence of pressure, i.e., by increasing the pressure. Thus, a higher vapor pressure corresponds to a lower boiling point and vice versa. We can calculate the boiling point by Clausius- clapeyron equation.

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