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Kerensa Baker

Determining the purity of an ester

Bob Spencer  Follow
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Oke I'll try my best. Can I distill? But what if there's still methanol in the mixture, isn't the proximity in boiling temperatures too large? Thanks for helping me, this forum is really helping me understand chemistry.

You have got the point here. If there are impurities in your mixture, the boiling point of it will increase(boiling point elevation). So, to test the purity of your own made methylacetate ester you can test its boiling point. If pure, the mixture should have a sharp boiling point(completely boils over a very narrow range of temperature) which matches the theoretical value of methylacetate ester (56.9°C, from Wikipedia).

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Dave G. Howell  Follow
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I also thought of gas chromatography, but methylacetate is liquid at roomtemperature (293 Kelvin). Is it possible to heat the solution first so that it evaporates and then add this gas to our chromatography setup?

You do not need to have the sample in the gas phase before you inject it to the GC, liquids work just fine.

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Olivia (Gloria)  Follow
Thank you so much! So by checking whether the boiling temperature is the same as what it should be for methylacetate, I'm able to find out whether this ester is pure or not. Awesome.

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Barbara Forbes-Lyons  Follow
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I also thought of gas chromatography, but methylacetate is liquid at roomtemperature (293 Kelvin). Is it possible to heat the solution first so that it evaporates and then add this gas to our chromatography setup?

Gas chromatography is possible, but you don't need it. The bold words in the quote is a hint. Try to think of something simpler :) .

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Boutros Gladius  Follow
Oke I'll try my best. Can I distill? But what if there's still methanol in the mixture, isn't the proximity in boiling temperatures too large? Thanks for helping me, this forum is really helping me understand chemistry.

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