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Thread: vinger too ethanol?

  1. #1 vinger too ethanol? 
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    Ethanol is easily oxidesed to vinger using saying Cr207(2-)/+h but does that mean if you used a reductant you could make vinger into ethanol?

    I'd appreciate any ideas..


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  3. #2  
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    if you distill any alcohol you will get pure ethanol or at least some proof of liquor depending on how fast/hot you do the process.

    but hasn't vinegar had the alcohol taken out? is that what you mean by oxidation? I always thought it was cooked off or something... I never understood where the flavor would come from, but oxidation makes more sense.

    I think you would need to de-oxidate it, but that doesn't sound easy, if it's even possible.

    By reduction you do mean evaporation right? I'm assuming that's what you mean, but you never know, it could be some chemistry technical term I'm not familiar with.


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  4. #3  
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    Theoretically, yes, but then there are a number of possible problems. And to the previous poster he means reduce acetic acid to give ethanol.

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    Thats how we learnt it. Stands for Oxidation Is Loss of electrons, Reduction Is Gain.
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    what are these possible problems i realize it may be slightly exothermic as it a condesation reaction. also i assume it needs some protons to fill the spaces could the supplying of protons from whatever source be the problem as ethanol can be used as a weak base. i imagine that could be problem the considering hte easiest source would be a strong acid
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    Well I supose the problems you encounter would depend on what you intend to use the alcohol for. Apparently Lithium tetrahydridoaluminate will reduce carboxylic acids to primary alcohols, but I've no idea where the equilibrium for that reaction lies. How would one seperate the alcohol from the acid? Would there be any ester formation? Could you seperate the reductant at the end of the reaction? Is vinegar pure acetic acid?
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  7. #6  
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    Yes, you can reduce acetic acid to make ethanol. There are many good reducing agents that can do it, but they'll all probably be more expensive than the value of the ethanol that you make with them. There are much easier ways to make ethanol (usually either fermentation of oxidation of ethylene).

    No, vinegar is not pure acetic acid - I think it's about 3-5% acetic acid in water.
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  8. #7  
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    I suppose it's possible, A strong enough chemical could theoretically strip out the oxygen added by the oxidation process

    I think you would probably need some form of catalyst though and it would ultimately just be cheaper to go and buy some ethanol
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  9. #8 Re: vinger too ethanol? 
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    Quote Originally Posted by Doomed Humanity?
    Ethanol is easily oxidesed to vinger using saying Cr207(2-)/+h but does that mean if you used a reductant you could make vinger into ethanol?

    I'd appreciate any ideas..
    Hello,

    Yes... acetic acid is easily reduced to give ethanol... using LAH - in the lab - and your body also has a biological pathway does this...

    hope this helps.
    Good luck..
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  10. #9  
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    Quote Originally Posted by farmboy
    Well I supose the problems you encounter would depend on what you intend to use the alcohol for. Apparently Lithium tetrahydridoaluminate will reduce carboxylic acids to primary alcohols, but I've no idea where the equilibrium for that reaction lies. How would one seperate the alcohol from the acid? Would there be any ester formation? Could you seperate the reductant at the end of the reaction? Is vinegar pure acetic acid?
    Hello,

    The carboxyllic acid can be reduced via lithium aluminum hydride... The equilibrium lies in the direction of the alcohol for this reaction because the alimunium hydroxide products formed are more stable than the aluminum hydride...
    Assuming that your reaction does not go in 100% yield there is nothing to worry about...

    you will have to do a work up anyway - which is common - so you will quench the reaction with water, the reductant will form aluminum salts that can be removed via filtration, you will then do basic extraction to remove any remaining carboxyllic acid in the event that you did not get a 100% yield... however this would be rare...

    This reaction is quite common... and is almost always quantitative.... H2 gas is formed during this reaction which helps drive equilibrium towards the product - the alcohol - and in fact this reaction is very exothermic so that is also a good indication that your products are more stable than your reactants, which is another parameter that favors equilibrium..

    hope this helps...
    good luck..
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  11. #10  
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    Quote Originally Posted by Scifor Refugee
    Yes, you can reduce acetic acid to make ethanol. There are many good reducing agents that can do it, but they'll all probably be more expensive than the value of the ethanol that you make with them. There are much easier ways to make ethanol (usually either fermentation of oxidation of ethylene).

    No, vinegar is not pure acetic acid - I think it's about 3-5% acetic acid in water.
    Typically only the aluminum hydride reagents will work on acetic acid and this is also true for other carboxcyllic acids...
    Due to the electronics of the carboxylic acid functionality it is more difficult to reduce them to the primary alcohol than it is to take an aldehyde to a primary alcohol...

    The first step in the reduction of a COOH to a primary alcohol is the formation of the carboxylate... looking at the mechanism you can see that this will form a salt with the Aluminum - which is often insoluble in the reaction mixture (also bad) - furthermore the newly formed anion is resistant to nucleophilic attack thereby slowing the reaction down to the point where a weaker reducing agent is not capable of meeting the required energy of activation in order to proceed to the primary alcohol...

    This can be related to the question in another thread regarding periodic trends... the fact that Al is oxaphilic helps to overcome some of these issues...

    thus in conclusion carboxylic acids require a stronger reducing agent....

    hope this helps...
    Good luck.
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