Questions tagged [distillation]
For questions about the process of distillation. For the distillation process used in metal refining, also use the [metallurgy] tag.
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Why is the composition of a liquified vapor the same as that of the vapor?
In Organic Chemistry Lab Techniques (Nichols), I found this diagram.
I understand that when going from Point $a$ to Point $b$, the composition becomes richer in the more volatile component (component ...
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35 views
How to handle CO2 being evolved during vacuum distillation?
Setup: vacuum aspirator pump, distillation apparatus with stirring (instead of a bubbler). Partial vacuum around 5" Hg.
What would you suggest to hold the vacuum set-point?
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1answer
58 views
Why does adding salt to water help distillation?
I've been looking at instructions on how to get lanolin from fleece and a lot of the instructions mention that adding salt to the water before distillation will increase the lanolin yield. Why is this?...
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20 views
Azeotropic Distillation - Am I interpreting this VLE diagram correctly?
I've been looking at ways to re-concentrate a formic acid-water binary mixture with the VLE diagram below.
Am I correct in saying that to concentrate a solution of say , 40% formic acid by weight I ...
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1answer
36 views
Distillation of methanol and water - Temperature Change
We tried the synthesis of methyl benzoate in the lab via the Fischer Esterification reaction with excess starting methanol. After 1 hour of refluxing the reactants we immediately set up a simple ...
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22 views
Does the distillation of alcohol cause the fractioning of isotopes and carbon-12 enrichment?
In water, distillation causes fractioning of the $\ce{^{18}O}/\ce{^{16}O}$ oxygen isotopes (Wikipedia).
Does something similar happen to the $\ce{^{13}C}/\ce{^{12}C}$ and possibly $\ce{^{14}C}$ ...
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23 views
Distillation of oxalyl chloride
May I use water as a condensing medium while distilling out oxalyl chloride?
As oxalyl chloride reacts with water and the products are $\ce{HCl},$ $\ce{CO}$ and $\ce{CO2},$ when there is a leak or ...
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1answer
43 views
When to use chromatographic separation vs vacuum-assisted rectification distillation?
I'm trying to understand a bit more about industrial scale separation processes. One particular element I'm interested in is the question as to when chromatography (HPLC or Simulated Moving Bed) may ...
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1answer
60 views
Will there be some ethanol evaporating before the boiling point of azeotrope? And will it bring some water with it because of the hydrogen bond?
Before the specific temperature, even if the temperature doesn't reach the boiling point of azeotrope or ethanol or water, we know that there are still some ethanol evaporate. In this time(before the ...
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1answer
73 views
Will distillation do the job of purifying the water?
I asked about my sophisticated water purification system for a generation ship on Worldbuilding Stack Exchange, and somebody mentioned this:
If you're gonna go to all the trouble of distilling it, ...
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1answer
29 views
Separate less volatile component from distilling a mixture [closed]
Is it a strict rule that when we boil a mixture of two liquids, with one being less volatile than the other, the more volatile vapour has to form the greater portion of the total vapours?
If it is so,...
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93 views
Can you heat something at alcohol bath?
I have a mixture of $\ce{Et2O},$ $\ce{EtOH}$ and water, and I want to distill off the ether. I am using a water bath so not much water is distilled over, as the boiling water is 100 °C, and the ...
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2answers
122 views
Glass joint stuck in flask
I am doing distillation using system of glassware including a flask and a glass joint. Recently I've faced a problem: the glass joint stuck in the flask. I tried to remove it but it broke and hurted ...
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1answer
61 views
Why does steam distillation work?
I'm aware that there is a similar question here but it didn't really answer my specific questions.
I understand that steam distillation is used to separate an insoluble liquid from an aqueous solution,...
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1answer
47 views
What are the components of a labware setup for short-path distillation?
I've recently become interested in short-path distillation and have found that most kits are in the thousands of dollars. So I thought that I would compile the labware myself.
I understand the theory ...
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1answer
60 views
Can I determine purity of isopropanol with a hydrometer?
Assuming I start with a known 99.8% purity of isopropanol, after recovery with a distillation apparatus, could I use a hydrometer to test for water content? If so, is there a special one I should use?
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49 views
Is there a way to form only ortho product without using fractional distillation?
Using benzene and ethane as your only source of carbon in the final molecule, synthesize the following using any useful reagents. Reaction must form pure ortho compound.
I have to form the ...
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1answer
199 views
Is 99% Isopropyl Alcohol sold in stores really 99%?
My understanding is that an azeotropic mixture of isopropanol and water is 91%. This makes sense as to why there are so many brands of rubbing alcohol sold at 91%. There are also some sold as 99%, ...
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2answers
191 views
At what position in the distillation apparatus does the temperature match the boiling point of the distilled substance?
A student is separating $\ce{CHCl3}$ (bp = $\pu{61 ^{\circ}C}$) from $\ce{CHCl2CHCl2}$ (bp = $\pu{146 ^{\circ}C}$) by distillation. She has just begun to collect the first distillate in the receiving ...
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1answer
101 views
Distillation: temperature not reaching azeotrope boiling point
I ran a simple distillation of $\ce{HBr}$/water mixture because I wanted to purify it. Boiling point of azeotropic hydrobromic acid is approx. $\pu{124 ^\circ C}$, however my distillation ran almost ...
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2answers
1k views
Use of fractional distillation in organic chemistry [closed]
Can fractional distillation be used to distinguish between:
1) d/l form of a compound
2) geometrical isomers of a compoun (Cis and Trans)
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2answers
106 views
Why we don't we save water by boiling the contaminated water to get the pure steam?
I see lot of drinkable water wasted in household and industrial activities, water usually gets contaminated with detergents(and other household materials),chemical effluents released from factories .
...
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1answer
298 views
Why is ethanol distilled off before adding water in the first step of a malonic synthesis?
I am doing a malonic synthesis shown below, and I wonder why I should distill ethanol off before adding water in the first step of the reaction (First I add absolute ethanol and solid sodium).
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1answer
45 views
Removing water/moisture from car exhaust [closed]
I know that car exhaust is almost entirely nitrogen, water and carbon dioxide. How would I go about removing the water? Would I have to condense it off? Any devices already exist for doing so?
2
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1answer
63 views
Double surface in the pressure temperature concentration curve for a binary mixture
In the 3 dimensional diagram given, when a constant pressure plane intersects with the double surface, it produces a looped curve without a maxima or minima. What is the double surface and how is the ...
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1answer
238 views
Last step of nicotine extraction using DCM
After using hydro-distillation method with distilled water and NaOH, separating the extract with dichloromethane, distillate it at 40 °C/104 °F, I'm left with some yellow pale oil.
I'm just wondering ...
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1answer
116 views
What is the difference, if there is, between this two distillation methods?
Reading about water vapor distillation, I found two differents approaches:
Direct one
Indirect one.
The first has an arrange like:
Here the chamber contains water and the plant. It is cooled and ...
3
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0answers
66 views
Do theoretical plates required to obtain a pure product decrease under vacuum distillation?
For this question I am using Ethanol as an example. The following is the vapor-liquid equilibrium diagram for Ethanol under atmospheric pressures.
Under reduced pressures do the number of theoretical ...
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0answers
34 views
What is the future of water treatment, and why we don't use enough purified sea and freshwater? [closed]
I understand thermal and membrane distillation are very expensive and that slowed down their usage, but now we can bring 100% clean energy to power them. Except the set-up, the price of materials and ...
3
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1answer
766 views
Isopropyl alcohol still leaves evaporation residue after distillation
I just finished distilling two liters of IPA because evaporating 5 ml on a watch glass revealed it to contain quite a bit of dissolved impurities. However, it still leaves some residue, even though I ...
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0answers
78 views
What causes both components of a binary gas mix to condensate at the same time for a given composition
Okay, so recently I encountered the temperature - mole fraction diagrams for binary vapour-liquid equilibrium. For now, I only consider two-component systems where the components are very similar and ...
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2answers
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Enrichment of D2O
The Wikipedia page for deuterium oxide (heavy water) says that its boiling point is 374.5 K and the one for ordinary water is 373.13 K.
Is there a way of distillation which we can use to enrich ...
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1answer
33 views
Vapour-Liquid Equilibrium
I have been studying flash distillation, and I am reading the VLE tables my textbook has provided.
I am looking at these tables and I am not understanding the data, I think.
Why is the vapour mole ...
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2answers
348 views
Do light and heavy water form an azeotrope?
(Interested in the general principle too, not just for water and its variants, but with particular emphasis on it.)
When you distill a weak ethanol-in-water solution, you get a condensate that's ...
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0answers
54 views
Is it possible to fractionally distill a compound made up of substances with very similar boiling points?
Let's say I have a solution that is made up of substances that have very similar boiling points, say less than 5 degrees apart. Is it even possible to fractionally distill those substances, say, using ...
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1answer
114 views
What is this glassware between flask and condenser to collect liquid?
I've been trying to identify this piece of glassware for ages now. I've been combing the internet and can't seem find anything similar. It looks like some kind of adapter/collecter/trap that sits on ...
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35 views
Distillery Transfer Hoses
I was hoping an actual person could offer me some advice. I work in a craft distillery and I'm getting a lot of mixed information on how compatible PVC is with high-proof alcohol. It definitely seems ...
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367 views
Column pressure control in distillation
In the industry , it's important to maintain the column pressure control in the distillation column .
" Pressure alterations will alter column vapour loads and temperature profiles. .
So when using ...
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1answer
2k views
Distillation of aniline/water mixture
I read from a source that aniline and water can be separated by steam distillation. But isn't this senseless as steam distillation will simply add more water and make separation more difficult?
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1answer
796 views
How can I remove water vapor from an airstream without a cold trap?
I'm trying to perform vacuum distillation at home with a rotary vane vacuum pump.
In order to not ruin my vacuum pump, solvent vapor (in my case, water) should be removed from the air before it ...
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2answers
6k views
How to increase the concentration of HCl
Today I have purchased some $\ce{HCl(aq)}$ on my local market with a concentration of 23%.
However, I need to obtain a concentration of 37% in order to perform an experiment. Can I use distillation ...
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1answer
49 views
Can liquids be made a lot purer than by fractional distilation?
Suppose you have a fused quartz tube with one closed end coiled into a spiral with a diameter of more than 10 m and you submerge it into a mixture of water and ethanol in a way that gets rid of all ...
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1answer
65 views
How does electrophoretic separation work in terms of separating soil into minerals?
I found this diagram and would like to know how it works with soil.
Google searches yield protein/biology things, anyone know how this method would work with soil?
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1answer
138 views
Would distilling a sodium fluoride solution generate hydrogen fluoride to any noticeable extent?
If you have a solution of NaF, and you boil it (to get pure water by distillation) can the fluoride ions in water separate from sodium ions and combine with hydrogen ions to form HF? ...
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699 views
How to get anhydrous triflic acid from triflic anhydride?
I require a small amount of triflic acid, and while other research groups do not have any, I did locate some trflic anhydride. Does anyone have a published protocol for obtaining the anhydrous acid ...
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6answers
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Un-denaturing industrial alcohol
I have a question regarding the denaturation of industrial ethanol with methanol to discourage its consumption.
The boiling point of methanol is 64.7 °C, while the boiling point of ethanol is 78.37 °...
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2answers
2k views
Condenser length?
I notice that Graham condensers tend to come in three main sizes: 200mm, 300mm and 400mm. What are the relative merits of each size?
My typical application is vacuum distillation of organic solvents ...
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Distillation for separating very close boiling components
When components of a mixture have very similar Boiling Points, say 2 C is distillation ever a viable separation procedure at industrial scale?
Assuming one were willing to install a very tall column,...
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4answers
177 views
To heat or not to heat; distillation?
One of the questions in a recent past paper I completed was:
One way to make water from the reservoir suitable for drinking is by distillation.
Describe how water is distilled.
And I answered ...
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1answer
294 views
How to separate benzyl alcohol and meta-cresol
Benzyl alcohol and meta-cresol boiling point's are not so different, the fractional distillation will be very difficult, what can i do for separate this two composites ?
