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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: Christiano on May 30, 2010, 11:06:13 am

Title: Formula of Ammonium Acetate
Post by: Christiano on May 30, 2010, 11:06:13 am

In the formula of Ammonium Acetate, CH3COONH4 (Ammonium - NH4 +) (Acetate - CH3COO -),  The rule of writing forumula says the positive ion is written first. Why isn't ammonium written first in this formula?

Title: Re: Formula of Ammonium Acetate
Post by: Twenty10 on May 30, 2010, 11:08:39 am

Coz when you draw the molecule out the NH4 bonds to the O.

Title: Re: Formula of Ammonium Acetate
Post by: Christiano on May 30, 2010, 11:16:46 am

Thanks. I picked this problem up in a practice exam when writing compounds, how do you know if a compound does not follow the standard rule of placing the positive ion first?

Title: Re: Formula of Ammonium Acetate
Post by: Potter on May 30, 2010, 12:08:49 pm

Quote from: Christiano on May 30, 2010, 11:16:46 am

Thanks. I picked this problem up in a practice exam when writing compounds, how do you know if a compound does not follow the standard rule of placing the positive ion first?

Afaik, the carboxylate ions are the only exceptions in vce and I think that examiners would accept NH4CH3COO or CH3COONH4.

Title: Re: Formula of Ammonium Acetate
Post by: Christiano on May 30, 2010, 12:23:37 pm

Thanks for the heads up