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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: XxslbabesxX on May 12, 2005, 07:36:08 PM

Title: How come CH3COOH is called acetic acid, but there's no H in front of it.
Post by: XxslbabesxX on May 12, 2005, 07:36:08 PM: I've learned that formulas for acids generally begin with H followed by whatever.

How come CH₃COOH is called acetic acid, but there's no H in front of it. I know this is a silly question probably with a simple answer, but it's bugging me. Thank you. :)
Title: Re:Acid Question
Post by: Borek on May 12, 2005, 07:57:10 PM: In chemistry there are usually more exclusions than rules ;)

Inorganic acids are usually written with H at the beginning of the formula.

Organic acids are written in many ways. Proton responsible for their acidity is a part of caroboxylic group. This group is usually written -COOH but sometimes -CO₂H.

Acetic (or ethanoic) acid is CH₃COOH, but it is sometimes written CH₃CO₂H or - even worse - C₂H₄O₂.

Don't bother, not formula counts but the molecule structure.
Title: Re:Acid Question
Post by: Mitch on May 13, 2005, 02:56:33 AM: Quote from: Borek on May 12, 2005, 07:57:10 PM

Don't bother, not formula counts but the molecule structure.

So true.
Title: Re:Acid Question
Post by: xiankai on May 13, 2005, 07:47:43 AM: CH3COOH is classified into 2 parts, the CH3COO- ethanoate ion and the H+ proton
Title: Re:Acid Question
Post by: Borek on May 13, 2005, 11:47:23 AM: I would rather split it into CH3- and -COOH, as this shows the structure and helps understand properties.
Title: Re:Acid Question
Post by: GCT on May 13, 2005, 12:19:48 PM: You seemed to be confused in the definition of acids and bases. Review the definitions, Arrehnius, Bronsted, Lewis. Acetic acid, has an acidic proton, and thus it qualifies as an Arrehnius acid.
Title: Re:Acid Question
Post by: XxslbabesxX on May 13, 2005, 05:19:41 PM: Quote from: GCT on May 13, 2005, 12:19:48 PM
You seemed to be confused in the definition of acids and bases. Review the definitions, Arrehnius, Bronsted, Lewis. Acetic acid, has an acidic proton, and thus it qualifies as an Arrehnius acid.

Yea, right now I'm learning all of that in my chem class, but it's just hard for me to understand. Looks like I got to hit the books this weekend.
Title: Re:How come CH3COOH is called acetic acid, but there's no H in front of it.
Post by: jdurg on May 15, 2005, 09:58:26 PM: Sometimes you'll even see acetic acid's formula written as HC₂H₃O₂ in order to emphasize that it is an acid. (Though this is generally only done in very introductory chemistry courses/books before organic chemistry is taught).