Previous Topic :Distillation
5] Separating funnel : is used to separate two or more immiscible liquids, what am saying is that separating funnel is used to separate two or more liquids that cannot mix together to from a single liquid (solution).
E.g kerosene and water or petrol and water.
NOTE : before you can use this method the two or more liquids must have different densities because that is what makes them immiscible.top↑
How To Separate Petrol And Water Using Separating Funnel
Petrol and water,
In the mixture it will be observed that the two liquid didn't mix together, petrol will be found floating on the surface of the water because it has low density that is, it is less denser than water and the water will be found at the bottom of the container because it has high density than petrol that is, it is denser than petrol, hence the liquids separate out to form a two distinct layers.
The mixture will be poured into the separating funnel, the funnel has a tap at the mouth, remember that in the solution, petrol will be at the top of the surface of the water so definitely it will be the petrol that will first get into the separating funnel but immediately as water goes into the funnel, the petrol will float again because petrol has low density and the water will be run out through the tap into another container leaving the petrol in the separating funnel which will also be run out into another container.top↑
Evaporation and Sublimation as a separating techniques
6] Evaporation : is the method use to obtain a soluble substance from it solvent.
If you haven't forget, when we treated filtration and distillation, I said, a solution is a mixture containing solvent and a solute, that solute is what dissolve in.. and solvent is what dissolve the solute that together they form a solution, and under mixture also, I also briefly explain how to separate NaCl solution.
So i will use NaCL(common salt ) and water to explain EVAPORATION.
When a salt is mixed with water to from a solution, the salt can be obtained back from the solution by heating the solution.top↑
When heat is apply to the solution, it will be observed that some water molecules will start leaving the surface of the solution, that process where water started leaving the surface of the heated solution to the atmosphere is called EVAPORATION.
NOTE : All water obtained from evaporation are pure, no matter what the solution is and if you tested an evaporated water and it contain impurities that means the condenser you used contain some impurities.
7] Sublimation : This method simply means a substance in solid form changes directly to gaseous form without passing through any liquid form and then back to solid form without passing through liquid form. Eg. A mixture of sulphur and ammonium chloride,top↑
Sulphur can be separated from ammonium chloride when heat is apply to it, ammonium chloride will sublime because it is a subliming substance and reforms as solid on the cool upper part of the inverted funnel or boiling tube, leaving sodium chloride in the evaporating dish.
Other examples are iodine, anhydrous aluminum chloride [AlCl3], benzoic acid [C6H5COOH], iron (iii) chloride [FeCl3] and Camphor.top↑
Question Of The Day
I have a question for you guys ,
What is the different between a Camphor and a Camphra?
Kindly use the comment box or use contact page
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