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Addison-Wesley Chemistry (5th Edition) Edit edition. Problem 14SR from Chapter What reactants are needed to make the ester propyl ethanoate? Get solutions. I was asked to make propyl ethanoate from propene in three steps. I have access to the reactions below. Nucleophilic substitution (Both SN1 and SN2) Electrophilic addition; Hydrogenation; Dehydration; Hydration; Condensation; Free radical substitution; Oxidation of alcohols.
Chemistry Stack Exchange is readtants question and answer site for scientists, academics, teachers, and students in the field of chemistry. It only takes a minute to sign up. Connect and share knowledge within a single location that is structured and easy to search. I was asked to make propyl ethanoate from propene in three steps. I have access to the reactions below.
I'm assuming that you can add whatever reactants you want, since propyl ethanoate has five carbons and you can't just chop a carbon off of a propene with the above reactions. I know that the final step has to be condensation, since that's how you make esters. So essentially, I need a two-step process to make a primary alcohol that becomes the propyl in propyl ethanoate. If you use hydrogenation on propene first, you get propane.
Once you have that, it takes two steps to make a primary alcohol: one in free radical substitution to get 1-bromopropane and one in nucleophilic substitution to get propanol.
If you use hydration first, you get a secondary alcohol in one step. However, you can't make propyl ethanoate with propanol. If you use electrophilic addition first, you get a secondary haloalkane 2-bromopropane.
That can also only get you a secondary alcohol. My proposal is hydroboration followed by Fischer esterification. It's 2 or 3 steps depending on how many you count propyp to be. This ethanoatf would have a lower yield though due to the competing E2 reaction. Oxidise propene to propenol with selenium dioxide. Here's a reference: J. The typical Fischer esterification with carboxylic acid and concentrated sulfuric acid should probably work, although there are many other possibilities.
One is to use the acyl chloride with a weak base. A common choice is 4-dimethylaminopyridine, often called DMAP.
The DCC activates the carboxylic acid in what is known as the Steglich esterification. Reduce the double bond by catalytic ethaboate. Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group.
Create a free Team What is Teams? Learn how to write a opinion letter. Asked what is the us doing about north korea threat years ago. Active 1 year, 6 months ago. Viewed 7k times. Nucleophilic substitution Both SN1 and SN2 Electrophilic addition Hydrogenation Dehydration Hydration Condensation Free radical substitution Oxidation of alcohols I'm assuming that you can add whatever reactants you want, since propyl ethanoate has five carbons and you can't just chop a carbon off of a propene with the above reactions.
Does anyone know how great white shark facts about what they eat do this? I'm convinced that it's impossible to do. Improve this question. Of course it becomes extremely simple if you use something outside of your syllabus, but well That would be helpful as well.
It's propyl ethanoate. Add a comment. Active Oldest Votes. Improve this answer. By the way, how do you draw such nice chemical equations? If you don't want to use my proposed one, the alternative one is definitely three steps. Do you think that I could do this with electrophilic addition in some special solution like a protic solution or in some special conditions like extreme temperature? Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password.
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ethanoic acid + ethanol ethyl ethanoate + water. + + H2O. sometimes more simply written as. CH 3 COOH + CH 3 CH 2 OH CH 3 COOCH 2 CH 3 + H 2 O. The reaction is reversible and the mixture reaches equilibrium, about 2 / 3 rds of the carboxylic acid and alcohol have been converted to the ester. To make a small ester like ethyl ethanoate, you can gently heat a mixture of ethanoic acid and ethanol in the presence of concentrated sulphuric acid, and distil off the ester as soon as it is formed. This prevents the reverse reaction happening. It works well because the ester has the lowest boiling point of anything present.
See also Carboxylic acids - structure, chemistry and uses. Doc Brown's. See also Carboxylic acids - molecular structure, chemistry and uses. Multiple Choice Quizzes and Worksheets. ALSO gap—fill 'word—fill' exercises originally written for Keywords and phrases: What are esters?
What are esters used for? How do you prepare esters? What do we need to make esters? What connects the chemists laboratory and the perfume industry! Carboxylic acids react with alcohols to form organic compounds called esters which are used as solvents and components in perfumes and food flavourings.
All relevant chemical equations are given. Doc Brown's Chemistry. Enter chemistry words e. Carboxylic acids are used to manufacture esters by reacting them with alcohols Carboxylic acids react with alcohols to form members of another homologous series called esters. Concentrated sulphuric acid acts as a catalyst in this reaction.
Without a strong acid catalyst e. Structures of other esters made from ethanoic acid: methyl ethanoate using methanol , and ethanoic acid propyl ethanoate from using propanol propan—1—ol, n—propyl alcohol and ethanoic acid. Note the arrangement of the atoms at the ester linkage, the functional group -COOC-. The first part of an ester's name is derived from the alcohol e. The second part of the name comes from the carboxylic acid and ends in The procedure for preparing an ester This is illustrated in the diagrams below and a detailed description of the method for preparing ethyl ethanoate is described.
Ethyl ethanoate and water are both colourless, but to help in following the procedure via the diagrams, I've coloured the ester yellow and the reaction mixture and aqueous solutions a pale grey. This is a detailed description that will do for Advanced A level chemistry too! Stage 1 in making an ester STAGE 1 Making the ester : In the round-bottomed flask the alcohol ethanol is mixed with the carboxylic acid ethanoic acid and a small amount of concentrated sulfuric acid catalyst is added too.
Anti-bumping granules are added to ensure a smooth boiling action. The mixture is carefully heated to get the mixture gently boiling and refluxing.
Stage 1 is a technique called ' heating under reflux ', and ensures the reaction occurs the fastest at highest possible reaction temperature, the boiling point of the mixture. The diagram shows a bunsen burner being used to supply the heat 'my days' , these days its more likely, and safer, to use an electrical heater that the round bottomed flask fits in snugly. Again the mixture gently heated and boiled, but this time you want the vapour of the lowest boiling component ester to separate out in the fractionating column and pass through into the condenser.
This happens when the temperature at the top of the column reaches the boiling point of the ester. The ester and small quantities of carboxylic acid, sulfuric acid and alcohol can be collected from the condenser in a suitable glass vessel. Preferably a quick-fit one that connects to the condenser, BUT it must not be a completely sealed system otherwise pressure would build up, hence the vent to the sink. You should realise at this point in the preparation that the ester ethyl ethanoate is very impure.
Stage 3 in making an ester STAGE 3 Removing acidic impurities : The rest of the procedure is all about purifying the initial ester distillate from the fractional distillation. The condensate liquid distillate from the fractional distillation apparatus is transferred to a separating funnel tap funnel.
Sodium carbonate solution is added to neutralise any acids and the stopper replaced. The separating funnel is shaken to ensure complete removal of the acid, but carbon dioxide is formed, so every so often you invert the funnel, open the tap and allow the gas to escape. When there doesn't seem to be any more effervescence or gas pressure, the mixture is allowed to settle. When the two layers have fully separated, the stopper is removed, and the lower aqueous layer is careful run off, don't lose any of the ester in the process!
When doing the run-off the stopper must be removed. The acidic impurities and any salts formed have now been removed in the aqueous sodium carbonate solution, therefore there should be no carboxylic acid or sulfuric acid catalyst left in the ester layer.
Stage 4 in making an ester STAGE 4 Removing the ethanol impurity : However, despite removing some impurities there will still be some traces of the alcohol left in the ester layer. Concentrated calcium chloride solution is added to the still impure ester in the separating funnel and the mixture shaken again. The aqueous calcium chloride will remove any remaining unreacted alcohol ethanol.
Again, the lower aqueous layer is tapped off to leave only the ester layer which will still contain some water. So, to dry the ester, it is run off tapped off from the separating funnel into a small conical flask and some granules of anhydrous calcium chloride added.
The conical flask is stoppered and the mixture shaken, and the calcium chloride absorbs any remaining moisture in the ester. The pure ester can than be filtered off. You can make butyl ethanoate and other esters by the same reaction and procedure. You can mix equal volumes of small quantities of a carboxylic acid and an alcohol with an even smaller volume of concentrated sulfuric acid. The mixture is gently warmed in beaker of warm water for minutes.
The mixture is then poured into a beaker of sodium hydrogencarbonate solution. The sodium hydrogencarbonate neutralises the acid catalyst and any unreacted carboxylic acid.
You should get some drops of ester left on the surface which can be carefully smelled to appreciate the aroma of the ester. You can do this is as a nice class experiment with ethanoic acid and a variety of alcohols and noting what they think the esters smells like likely to be 'fruity' alongside appreciating its molecular structure too!
This reaction is called hydrolysis or saponification i. Perfumes can natural, obtained from plant sources, or artificial, since esters are readily synthesised in the laboratory. Natural substances are used in many cosmetics but many mixtures contain synthetic organic compounds. Many esters have pleasant sweet or fruity smells and the colourless liquids are quite volatile, that's why fruits have strong pleasing odours or aromas.
The pleasure of most flavours and fragrances from fruits is due to esters, the vapours from esters definitely entice the receptors in your nose to feel good!
How and why do we smell perfumes? Therefore, in order to smell a substance, that substance must be to some extent be a volatile material. If a substance isn't volatile, you are highly unlikely to smell it i. The most volatile materials are those that most easily evaporate e. The intermolecular forces between molecules are relatively weak in liquids that are volatile, so the particles don't need to much kinetic energy to escape from the surface of your skin.
Because of random collisions, the particles in a liquid have a variety of speeds and kinetic energies. Evaporation occurs all the time from volatile liquids, but it is the higher kinetic energy particles that can overcome the attractive forces between the molecules in the bulk of the liquid and escape from the surface into the surrounding air.
It is these higher kinetic energy escaped molecules that diffuse through the air to reach the receptor cells in the nostril to trigger the sense of smell. That is why perfume molecules must be quite volatile to work, but they must be not too volatile or their effect won't last very long. On heating particles gain kinetic energy and move faster and are more are able to overcome the intermolecular forces between the molecules, therefore theoretically, perfumes should smell stronger in a warmer room.
Because they are volatile and pleasing to the nostril, it makes esters ideal for cosmetic perfumes and cosmetic fragrances in general, but esters are also used in air fresheners e. Because fruit sources are limited, many esters are now synthesised in large quantities so the flavourings and derived taste and aromas in fruit drinks, sweets and cakes etc. Esters are used in pharmaceutical and household products e. Examples of plant ester sources : Lavender oil essence is distilled from the lavender plant Examples of flavouring esters : Pear drop sweet essence is an ester.
Factors affecting perfume design e. You can't just use any ester, no matter how beautiful it smells. The chemicals in cosmetic perfumes must have a particular set of properties including The perfume needs to be a mixture of compounds to give a prolonged perfumery effect. The perfumer chemist has to design the mixture to give a particular fragrance which includes Cosmetic companies are always developing new products to comply with our aesthetic desires!
BUT, every new product must be thoroughly tested before it is ready for the consumer. Unfortunately, this sometimes involves using animals e. Opinions can be strongly divided and divisive as to the merit and ethics morality of using animal testing for new cosmetic formulations and of course using animals to test new medicines from the pharmaceutical industry.
One view is that animal testing is worth it to avoid possible adverse effects on consumers, so any discomfort or worse, suffered by the animals to prevent us suffering in the same way, a sort of 'health and safety' issue argument. The opposing view argues that it is entirely wrong to use animals in tests. So, because of concerns about animal welfare in conducting tests of cosmetics on animals, the European Union EU has banned almost all of these animal test procedures.
Some larger ester molecules are used in plastic formulations as plasticisers which are added to make the polymer more flexible. They aren't totally free of health issues but esters have replaced more harmful aromatic hydrocarbon solvents like benzene a carcinogen — a cancer promoting chemical and methylbenzene old name toluene, also carcinogenic in paint and varnishing products.
BUT take care The vapour is heavier than air and will not disperse quickly, iii some people may be allergic to ester fumes, or indeed their use as food additives.
Why does a substance dissolve in one liquid solvent but not another? There are three particle interactions going on if you mix one substance with another e. The three possible attractions are i solid The relative strength of these attractive intermolecular forces decides whether e. For example, nail varnish will not dissolve in water, but will dissolve in organic solvents like an ester, alcohol or acetone.
Nail varnish is insoluble in water because the intermolecular forces between the nail varnish molecules themselves, and between the water molecules themselves are much stronger than the attraction between water and the nail varnish molecules, so the nail varnish cannot possibly dissolve in water. Forces i and iii override force ii However, nail varnish will dissolve in organic solvents like butyl ethanoate or ethyl ethanoate esters, old names butyl acetate and ethyl acetate , ethanol 'alcohol' and propanone old name acetone solvents.
Here the organic solvent intermolecular attraction to the nail varnish molecules can override the nail varnish
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