Nama/NIM: Muhamad Syaiful Ampri/Kelompok: Kimia () Judul: “ HUKUM RAOULT” ALAT dan BAHAN. Contoh campuran ideal. Campuran ideal dan perubahan entalpi pada proses pencampuran. Hukum Raoult Tekanan uap / diagram komposisi. Raoult’s law (Q) François-Marie Raoult hywiki Ռաուլի օրենքներ; idwiki Hukum Raoult; itwiki Legge di Raoult; jawiki ラウールの法則; jvwiki Hukum .

Author: Samushura Vudozuru
Country: Pakistan
Language: English (Spanish)
Genre: Business
Published (Last): 18 July 2015
Pages: 162
PDF File Size: 11.22 Mb
ePub File Size: 16.5 Mb
ISBN: 856-4-48390-621-2
Downloads: 85490
Price: Free* [*Free Regsitration Required]
Uploader: Mezizil

For two liquids at the same temperature, the liquid with roult higher vapor pressure is the one with the lower boiling point. If the proportion of each escaping stays the same, obviously only half as many will escape in any given time. The definition below is the one to hu,um if you are talking about mixtures of two volatile liquids. Therefore, the liquid with the higher vapor pressure at a particular temperature is the one with the lower boiling point.

Hukum Raoult dan Destilasi Fraksional by burhan gopur on Prezi

That means that molecules must break away more easily from the surface of B than of A. That means that in the case we’ve been talking about, you would expect to find a higher proportion of B the more volatile component in the vapor than in the liquid.

The net effect of that is to give you a straight line as shown in the next diagram. Solubility equilibrium Total dissolved solids Solvation Solvation shell Enthalpy of solution Lattice energy Raoult’s law Henry’s law Solubility table data Solubility chart. In a perfectly ideal system, where ideal liquid and ideal vapor are assumed, a very useful equation emerges if Raoult’s law is combined with Dalton’s Law. Ideal Mixtures An ideal mixture is one which obeys Raoult’s Law, but I want to look at the characteristics of an ideal mixture before actually stating Raoult’s Law.

If the deviation is large, then the vapor pressure curve shows a maximum at a particular composition and form a positive azeotrope. Note that a few countries have copyright terms longer than 70 years: If that is not obvious to you, go back and read the last section again! Some mixtures in which this happens are 1 benzene and methanol2 carbon disulfide and acetoneand 3 chloroform and ethanol.


If the vapor pressure is less than predicted a negative deviationfewer molecules of each component than expected have left the solution in the presence of the other component, indicating that the forces between unlike molecules are stronger.

These are mixtures of two very closely similar substances. If you boil a liquid mixture, you can find out the temperature it boils at, and the composition of the vapor over the boiling liquid. Exactly the same thing is true of the forces between two blue molecules and the forces between a blue aroult a red. The smaller the intermolecular forces, the more molecules will be able to escape at hukkum particular temperature.

Retrieved from ” https: In fact, it turns out to be a curve.

This work is in the public domain in its country of origin and other countries and areas where the copyright term is the author’s life plus 70 years or less. This is called its partial pressure and is independent of the other gases present. From Wikipedia, the free encyclopedia. This law is known as Henry’s law. The vapor pressure of pure methanol at this temperature is 81 kPa, and the vapor pressure of pure ethanol is 45 kPa. Views View Edit History.

It covers cases where the two liquids are entirely miscible in all proportions to give a single liquid – NOT those where one liquid floats on top of the other immiscible liquids. In a pure liquid, some of the more energetic molecules have enough energy to overcome the intermolecular attractions and escape from the surface to form a vapor. Suppose that you collected and condensed the vapor over the top of the boiling liquid and reboiled it.

For mixtures of A and B, you might perhaps have expected that their boiling points would form a straight line joining the two points we’ve already got.

This is always negative, so mixing is spontaneous. The converse is true for positive roault. However the expression is, apart from a factor — Tequal to the entropy of mixing. If the temperature rises or falls when you mix the two liquids, then the mixture is not ideal.

The first factor is a correction for gas non-ideality, or deviations from the ideal-gas law. They must also be the same otherwise the blue ones would have a different rzoult to escape than before. In equation form, for a mixture raouot liquids A and B, this reads: You can discover this composition by condensing the vapor and analyzing it. In consequence, the relative lowering of vapour pressure of a dilute solution of nonvolatile solute is equal to the mole fraction of solute in the solution.


Let’s focus on one of these liquids – A, for example. That means that there are only half as many of each sort of molecule on the surface as in the pure liquids.

Raoult’s Law and Ideal Mixtures of Liquids

The mole fraction of B falls as A increases so the line will slope down rather than up. When the cohesive forces between like molecules are greater than the adhesive forces between dissimilar molecules, the dissimilarities of polarity leads both components to escape solution more easily.

However, the interactions in a liquid are very strong. There are two ways of looking at the above question: This phenomenon is the basis for distillation. For the purposes of this topic, getting close to ideal is good enough!

That would give you a point on the diagram.


The total vapor pressure of hukmu mixture is equal to the sum of the individual partial pressures. One can see that from considering the Gibbs free energy change of mixing:. What do these two aspects imply about the boiling points of the two liquids? The P o values are the vapor pressures of A and B if they were on their own as pure liquids. If you plot a graph of the partial vapor pressure of A against its mole fraction, you will get a straight line.

That means that you won’t have to supply so much heat to break them completely and boil the roault. You would now be boiling a new liquid which had a composition C 2.