What is the enthalpy of vaporization of a compound?
What is the enthalpy of vaporization of a compound?
Introduction. The enthalpy of vaporization (ΔHV, given in units of kJ/mol) is the energy that must be supplied to a unit molar amount of a pure compound to transfer it from the liquid state to the gaseous state at a constant temperature and at the corresponding vapor pressure. Its usage is very widespread.
What is the enthalpy of vaporization of water?
Water is present in many experiments but it is important to realize that its enthalpy of vaporization is very high, 43.9 kJ mol−1 at 25 °C [9]. In the reaction calorimetry of some mixtures this would be of the same order as the heat production.
How do you calculate entropy of vaporization?
The entropy of vaporization was determined using Equation (4) (Trouton’s Law) by dividing ∆Hvap of water by its normal boiling point temperature in Kelvin (100.0˚C, 373.2 K); this resulted in a ∆Svap of 116.3 J/mol∙K for water.
What affects enthalpy of vaporization?
Vaporization occurs with a phase change and heat transfer, which can be observed as a cooling effect in the residual solution. In this process, the enthalpy of vaporization (ΔHvap) is the amount of heat required to vaporize any liquid from pure or solution form, at a constant temperature, pressure, and concentration.
How do you calculate enthalpy of vaporization from boiling point?
Tc = 647.3 K and Pc = 221.2 bar (218.3 atm), the heat of vaporization is obtained as 42,060 J/mol….[edit] Using Riedel’s equation.
| where: | |
|---|---|
| Hv | = Heat of vaporization, in J/mol |
| R | = 8.3144 = Universal gas constant, in J/(K mol) |
| Tn | = The liquid’s normal boiling point, in K |
| Tc | = The liquid’s critical temperature, in K |
What is the enthalpy of vaporization of ethanol?
42.4 kJ mol^-1
Ethanol boils at 78.4^oC and standard enthalpy of vaporization of ethanol is 42.4 kJ mol^-1 .
What is the enthalpy of vaporization of ammonia?
The enthalpy of vaporization of ammonia is 23.35 kJ/mol at its boiling point (-33.4 degrees Celsius).
What is the correlation between enthalpy of vaporization and intermolecular forces?
The stronger the intermolecular forces, the higher the heat of vaporization.
How is boiling point related to enthalpy of vaporization?
In general, the higher the boiling point is, the higher the heat of vaporization will be. However, there are some molecules that break this trend. For example, ammonia has a higher heat of vaporization than you’d expect based on its boiling point relative to other molecules with similar boiling points.
Which substance has the highest heat of vaporization?
of water
2 Heat of Vaporization. The heat of vaporization of water is the highest known. The heat of vaporization is defined as the amount of heat needed to turn 1 g of a liquid into a vapor, without a rise in the temperature of the liquid.
