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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18
votes
6answers
8k views

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 °...
11
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2answers
7k views

Proper use of vacuum pump during vacuum distillation

I am preparing to do a vacuum distillation and am unsure exactly how to manage the vacuum. The vacuum pump I have is a two-stage rotary vane pump which is capable of 250 microns or lower. It has a ...
9
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2answers
390 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 ...
8
votes
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 ...
7
votes
1answer
1k views

Vacuum distillation apparatus selection and configuration

I want to assemble a "hobbyist-level" vacuum distillation apparatus for extracting small volumes of "typical" solvents (e.g., water, alcohols, ketones, diols). I already have standard lab glassware ...
6
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3answers
10k views

Isopropyl alcohol forming peroxides

I read in many MSDS that Isopropyl alcohol tends to form peroxides (by reacting to air OR light) which may explode when they reach a given concentration. For example: http://nj.gov/health/eoh/rtkweb/...
6
votes
1answer
652 views

steam distillation of 4-bromoaniline , why render it basic prior

In the multistage synthesis of 4-bromobenzenamine, why must the solution be rendered alkaline prior to the steam distillation after the hydrolysis of 4-bromo-N-ethanoylbenzenamine?
5
votes
3answers
7k 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 ...
5
votes
4answers
216 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 ...
5
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1answer
109 views

N2O production vs air distillation

After producing nitrogen by distilling air, how is that nitrogen used with the oxygen to yield nitrous oxide ($\ce{N2O}$)? I see $\ce{N2O}$ available in different purities from various suppliers, but ...
5
votes
1answer
163 views

Drying a distillate liquid

So I'm carrying out the distillation of some essential oil and I have to remove the water content in it. The usual method is using diethyl ether but I'm looking for a greener method. What can I do?
5
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0answers
110 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 ...
4
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1answer
8k views

How to calculate mole ratio of two volatile compounds in distillation?

I have two volatile compounds (such as ethyl acetate and ethyl propionate). I am going to separate these compounds by simple and fractional distillation. How do I calculate mole ratios of the two ...
4
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2answers
2k views

Internal vs external steam distillation

To extract essential oils from plant matter (amongst other purposes), steam distillation is often used. I've seen a lot of different glassware setups for this. I've sometimes seen them broken into two ...
4
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2answers
3k views

Choosing a vacuum pump for fractional distillation

I have a fractional distillation setup. I would like to purify a small mixture ($\pu{\approx 100-150 mL}$) of high boiling point compounds (between $200$ and $\pu{300^\circ C}$). The one that ...
4
votes
1answer
1k views

Simple distillation & azeotropes

In my organic chemistry lab, we recently had an experiment where we were given a mixture of 50:50 ethanol & ethylene glycol. We were supposed to perform a simple distillation to calculate the ...
3
votes
1answer
344 views

Freeze distillation: Does efficiency depend on solubility?

I was surprised to learn that freeze distillation has the same inefficiencies as vapor distillation: Namely, that it is impossible to get two miscible fluids to fully separate in one "pass" of ...
3
votes
1answer
202 views

Fractional distillation of a product differs from the components listed in the SDS. What am I doing wrong?

I recently bought a product called Prestone De-Icer for Windows and Wipers which claimed to contain Methanol. I was puzzled when using it to note that it did not smell much like Methanol so I looked ...
3
votes
1answer
123 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 ...
3
votes
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 ...
3
votes
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 ...
3
votes
1answer
70 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?
3
votes
1answer
365 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).
3
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0answers
90 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 ...
2
votes
1answer
1k views

Vacuum-jacketed distilling column

I was looking for some distillation equipment on Sigma Aldrich because I wanted to perform some vacuum distillation, when I came across a vacuum-jacketed distilling column. Now as far as I understood ...
2
votes
1answer
1k views

Deuterium depleted water through fractional distilation

Could a packed fractional still of the same type used to distill ethanol to 95% be used to produce deuterium depleted drinking water? The still has a 1000 watt electric heating element and has a ...
2
votes
1answer
538 views

Distilling small volume

I have 50 ml of a compound I would like to purify. Since the impurities presents have close boiling points (b.p.), I have to use fractional distillation. Am I going to lose significant quantity of my ...
2
votes
1answer
2k views

Most efficient way to purify household vinegar: distillation or freezing?

I am aware that there are better ways to purify acetic acid out of a water-acid mixture than these, but which one out of distillation (using heat) and fractional freezing (using cold) would gain a ...
2
votes
1answer
192 views

Does Dean Kamen's Slingshot really filter virtually everything?

According to Dean Kamen (in the movie http://www.imdb.com/title/tt3242934/) and on the Net (http://www.popsci.com/article/science/pure-genius-how-dean-kamens-invention-could-bring-clean-water-millions)...
2
votes
1answer
77 views

Synthesis of phosphonate salt not working

I have tried four times in the past few weeks to synthesise 2-ethoxyvinyl phosphonyl dichloride by reacting ethyl vinyl ether with phosphorus pentachloride in toluene. I have been following the ...
2
votes
1answer
54 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 $\ce{^{14}C}$ ...
2
votes
1answer
70 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 ...
2
votes
1answer
119 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 ...
2
votes
1answer
135 views

Is the 'sweat' on the side of bottles distilled water?

Are the water droplets that form on the side of water bottles (or other drink containers) distilled water? Assume that the sides of the container are completely clean.
2
votes
1answer
473 views

What is this glassware for a distillation apparatus called?

I'm messing around with building a solar distillation apparatus, and one of the parts I think I need looks kind of like the following, except I have no idea what it is called (and thus can't look it ...
2
votes
1answer
53 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
votes
0answers
59 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 ...
2
votes
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 ...
2
votes
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 ...
1
vote
2answers
241 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 ...
1
vote
2answers
127 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 . ...
1
vote
1answer
2k views

Steam Distillation - Condensate not going through condenser

Basically what the title says. I set my equipment up exactly like pretty much every diagram I could find. There's condensation through the claisen adapter and into the distillation adapter, but for ...
1
vote
3answers
9k views

Cracking of dicyclopentadiene - was my simple Liebig condenser distillation setup adequate?

I recently did a distillation of dicyclopentadiene (bp 166 °C) to get cyclopentadiene (bp 40 °C). The setup as instructed by my supervisor consisted of a simple water-cooled Liebig condenser. Oil bath ...
1
vote
1answer
369 views

Precipitate Sodium Hypochlorite from tap water before distillation

Is there a fairly simple way to precipitate Sodium Hypochlorite from tap water before I distill it? Or, second best, a way to neutralize it?
1
vote
1answer
149 views

Extract acid from a solution

I have a solution containing glucose and some sulfuric acid. I want to distill out the sulfuric acid to then reuse it for other purposes. The problem is the presence of glucose in the solution. I'm ...
1
vote
1answer
52 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 ...
1
vote
2answers
311 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 ...
1
vote
1answer
307 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 ?
1
vote
1answer
90 views

opperating a distillation column far from flooding

I know that flooding will ruin the performance of a distillation column. There are many correlations (Eckert, kister, billet, etc.) that will tell you when a column will flood based on your fluid ...
1
vote
1answer
565 views

Fractional vs Simple distillation

After performing both simple and fractional distillations for a 50/50 mixture of methyl acetate/ethanol, i discovered that my total recovery (in mass) of substances after distillation was lower for ...