Citric acid uses

[Nevermore]

I bought some citric acid yesterday, and have yet to find a use for it. Other than culinary applications, what can I do with it?

[raivo]

You can make some CO2 by dissolving citric acid in water and adding some sodium carbonate or bicarbonate.

 

You can make citrates by reacting it with some freshly prepared carbonate or hydroxide but AFAIK citrates are not particulary interesting compounds.

[YT2095]

electrolysis of it will yield Acetone, again, not fantasticly interesting, but it does work

[woelen]

Citric acid is a fascinating chemical, when combined with transition metals. It forms nicely colored complexes with most transition metals, especially, when the pH is brought to a value higher than 7. The most remarkable complexes are formed with vanadium in its +4 oxidation state (easy to make from V2O5, which is a common chemical), and with copper in its +2 oxidation state and iron in its +3 oxidation state.

 

With iron in its +3 oxidation state, you can make a nice light sensitive chemical. Do a google with "cyanotype". This is a very neat experiment, which only requires an iron (III) salt, some citric acid and red prussiate of potash (potassium ferricyanide).

[Hephaestus]

Whats the voltage you need to make acetone? Interesting.

[YT2095]

it`s not really critical to be honest, but I wouldn`t go below 2.5 or above 6 volts really.

 

and although it Will generate acetone, Please don`t ask How you would Isolate this, it simply wouldn`t be worth doing, it`s just something Interesting that happens

[woelen]

You can also make acetone out of it by oxidizing it with any oxidizer, such as KMnO4, K2Cr2O7, Na2S2O8, etc. This reaction is slow and requires some heating, but it works. You can smell the acetone easily. It is, however, not interesting as a preparative route for acetone, it is just interesting as a curiousity.

[Hephaestus]

Not interested in the economical prep of acetone. Just nice to say Ï've done that. Would you believe all those oxidants are now illegal for purchase by individual in Australia without licence. Not hard to make though, and got plenty.

 

Anaerobic digestion of tartaric acid by microbes yields butanoic acid. Does citric acid get converted to anything interesting?

[woelen]

Indeed, I've heard of more people from Australia that their rules on chemicals indeed are insanely strict. Over here, where I live, chemicals are not that easy to find, but only few chemicals are illegal for purchase. In fact, compounds like K2Cr2O7, KMnO4, Na2S2O8 can be purchased in many shops like electronics stores, ceramics/pottery suppliers and the well-equipped online photography shops.

[bob000555]

You can also make acetone out of it by oxidizing it with any oxidizer, such as KMnO4, K2Cr2O7, Na2S2O8, etc. This reaction is slow and requires some heating, but it works. You can smell the acetone easily. It is, however, not interesting as a preparative route for acetone, it is just interesting as a curiousity.

 

Interesting what would the chemical formula for that be and why isn’t the acetone oxidized as soon as it made.

C6H807+KMnO4->C3H6O+???

[woelen]

The reaction between citric acid and an oxidizer is very complicated. Acetone is one of the reaction products, but there are many more. Also CO2 is formed.

 

The reaction requires acid as well. Writing a chemical equation of this reaction does not make real sense. Sometimes it hardly makes sense to write such equations, because the reactions are not clean and simple, but many reactions occur at the same time in unknown ratios.