Chemical Forums
Chemistry Forums for Students => High School Chemistry Forum => Topic started by: Jason2103 on May 12, 2008, 07:33:40 PM
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We did a lab at school in which the antacid Eno, whose active ingredient is Sodium Citrate Na3C6H5O7, is dropped in hydrochloric acid and I need to determine the reaction. Our teacher told us that the sodium is not involved, and to do the reaction as if it did nor exist, leaving me with
C6H5O7(s) + HCl(aq) ------->
I am not sure how to react these two compounds. My initial thought was to treat it like a neutralization reaction, resulting in H2O and the remaining salt composed of Carbon, Chlorine, and hydrogen, but that certainly doesn't seem like a salt at all. I also thought of just adding the H from the acid to the citrate, but there is no real science behind that choice. Can anyone help me out?
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Have you heard term "dissociation"? Do you know what "net ionic" reaction is? Na+ are spectators, but that doesn't mean you can just remove Na from the trisodium citrate formula - you have to account for their charge.
After that it won't hurt to read about the Bronsted-Lowry definitions of acid and base (http://www.chembuddy.com/?left=pH-calculation&right=bronsted-lowry-theory).
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whose active ingredient is Sodium Citrate Na3C6H5O7,
No criticism of you, you are working with what is given - I don't understand why "organic" formulae are given in that way - with no hint of the structure of the molecule.
For me, organic is all about the reaction of functional groups - which you can't start on with the formula that you have been given.
Is it an alcohol, or aldehyde, or ketone, or carboxylic acid, or some, or all or none . ???
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C6H5O7(s) + HCl(aq) ------->
I am not sure how to react these two compounds. My initial thought was to treat it like a neutralization reaction, resulting in H2O and the remaining salt composed of Carbon, Chlorine, and hydrogen, but that certainly doesn't seem like a salt at all. I also thought of just adding the H from the acid to the citrate, but there is no real science behind that choice. Can anyone help me out?
My suggestion is
1. Look up the structural formula of citric acid (find its modern name too) - the structure is quite "attractive" and much more informative than what you have been given.
2. See if you can deduce a formula for sodium citrate - because you have Na3 you want what is called the trisodium salt
3. Follow Borek's suggestions on acid / base
HTH
Clive