Metal finishing Q&As since 1989

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What is citric acid made of?

I have a science project due soon. what is citric acid made up of?

Brandon T [last name deleted for privacy by Editor]
- Berwyn, Illinois
2005

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citric acid is made of...citric acid . It's a pure compound. If you want a good start on finding out about it, try looking it up in a reference book called The Merck Index [affil link on Amazon].

Good luck with your project.

Dave Wichern
Consultant - The Bronx, New York
2005

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2005

That's a bit of a loaded and vague question, first you need to consider, what kind of citric acid ? Is it the acid in carbonated drinks? The kind in lemonade? The stuff used in food preservation? Or for industrial applications? Each one has a slightly different variation on the same elements

HOC(COOH)(CH₂COOH)₂.H₂O

Remove the H₂O if you are looking at the powdered stuff.

This will give you a direction I hope, good luck and try to be a bit more specific about what you need.

Marc Banks
- Elizabeth City, North Carolina

I want to know how I can get citric acid by itself from lemon juice. What things do I need? Can the lemon juice itself be substituted as citric acid in a chemical reactions experiment? I am in the 8th grade.

Alana C [last name deleted for privacy by Editor]
student - Stockton California
2007

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2007

Hi, Alana.

Unfortunately, an extraction like that would be beyond most college chemistry students. If you want citric acid , I think you will probably need to buy it rather than extracting it from lemons. Good luck.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

hi, I have also have a science project due, and I wanted to know what element citric acid is? thanks.

Cassady S [last name deleted for privacy by Editor]
student - Boston, Massachusetts
May 20, 2008

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May , 2008

Hi, Cassady. citric acid is not an element, it is a compound. The formula already appears on this page. What is your science project? Please tell us what grade you are in so we can try to explain citric acid in terms which you can understand. Thanks.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

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August 8, 2008

Citric and lactic acids are produced by fermentation which utilized a carbohydrate source such as corn based starch and sugar beet molasses. Fermentation yields a crude purity product which requires further refining. One refining technique utilities a precipitation process, this process first uses lime to produce calcium citrate solids, this is then contacted with sulfuric acid which produces a partially purified soluble citric acid and calcium sulphate by product. Another technique used is solvent extraction. These processes produce streams which require demineralization by ion exchange.

citric acid can be extracted from the juice of citrus fruits by adding calcium oxide (lime) to form calcium citrate, an insoluble precipitate that can be collected by filtration; the citric acid can be recovered from its calcium salt by adding sulfuric acid.

citric acid is obtained also by fermentation of glucose with the aid of the mold Aspergillus niger and can be obtained synthetically from acetone [on eBay or Amazon] or glycerol.

Camen Morris
- Burleson, Texas