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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Is there such a thing as a temperature-controlled reflux column?
You know the deal - you're doing a distillation in the lab, but want a fraction that comes over at a very specific temperature. I find it very hard to control the temperature in my air-cooled reflux ...
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70 views
Is it possible to vacuum distill citric acid?
I'm wondering if
it is at all possible to vacuum distill citric acid without the slightest decomposition;
it is something that can easily be done in a small lab with widely available equipment.
I've ...
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22 views
How concentrated does sulfuric acid need to be for nitric acid synthesis (H2SO4 + nitrate salt distillation)?
So I have a home lab setup and recently found myself in need of some nitric acid. I could just buy some, but I thought it would be a useful exercise to make my own. I have plenty of nitrate salts ...
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1answer
76 views
Are all gases equal in their ability to carry with them lower volatility matter at a given temperature? [closed]
As we all know water is a great solvent in it's liquid form relative to other substances. I wonder however how it performs as a gas relative to other stuff.
Does anyone know how well steam carries ...
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1answer
74 views
Why is the temperature graph sigmoidal in simple distillation of components with very different bps?
I'm writing an organic chemistry lab report on distillation and I thought I understood this, but the more I look at my lab textbook, I realize I don't. My textbook 1 explains that the temperature of ...
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30 views
Strange Distillation Behavior
I was attempting a fractional distillation with 1mL water and 1mL propylene glycol, and I’ve been encountering strange behavior with the heating of the mixture. The heating curve shows strange “spikes”...
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1answer
62 views
Driving force in distillation
If the pressure is lowered in a distillation column, then the equilibrium curve will move further away from the diagonal (bulge out more) in an equilibrium diagram. This leads to a decrease in ideal ...
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1answer
117 views
when using glass to glass stoppers, is it best to have them dry or use lubricant?
I have some glass flasks that have glass stoppers. It’s basically the typical glass stopper with the frosted tip which fits into a glass opening. Basically think of a typical glass volumetric flask. i ...
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29 views
Is the width of a Soxhlet Condenser Inherent to its Function?
Soxhlet extractors are often coupled to a specifically designed condenser with a very large lower joint.
Is this inherent to it's function as a condenser in the apparatus or only because the Soxhlet ...
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1answer
92 views
Laboratory setup for the distillation of sulfuric acid
Purification of Laboratory Chemicals, 5th Edition, by Armarego, reads (p. 53):
Reagents such as water, ammonia, hydrochloric acid, nitric acid, perchloric acid, and sulfuric acid can be purified via ...
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124 views
Distilling milligram quantities of oil like it's late 1970s
In a currently retracted* manuscript by Tomas Hudlicky [1, Retraction Watch] the following has been noted:
Fifty years ago professors took an active part in all laboratory instructions and they ...
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1answer
132 views
can i use an isobutane stove (like jetboil) or butane blowtorch with borosilicate glass?
I don't have a bunsen burner, but have a camping stove (similar to https://www.amazon.com/Stansport-183-B-Isobutane-Backpack-Stove/dp/B004EPWM5S) and a blow torch. I'd like to do some distillation ...
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294 views
When exactly does the first drop of distillate appear in a distillation?
The below image (source: here) is from a fractional distillation of a mixture of two liquids, one with a boiling point of 69 degrees celsius and the other with a boiling point of 98 degrees celsius. ...
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31 views
Reason for rounded fitting at the top end of Allihn Condenser
I am purchasing an essential oil distillation setup. The Allihn Condenser at the top end, and the attached glassware, are rounded. It is supposedly 24/40. I have never seen this. If one of them broke, ...
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1answer
48 views
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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37 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
84 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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24 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
190 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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1answer
59 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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0answers
100 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
77 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
152 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
80 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
55 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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2answers
181 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
417 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
79 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
86 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
479 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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63 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 product ...
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1answer
965 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
483 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 ...
3
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1answer
141 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
2k 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
190 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
408 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
69 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?
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1answer
75 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
267 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
253 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
108 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
35 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
1k 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
85 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
1k views
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
39 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 ...
9
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2answers
418 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 ...
2
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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 ...
2
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1answer
126 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 ...
