So according to the rules of solubility all ionic compounds containing acetate are soluble in water. However acetic acid is a weak acid. Why is this if acetate is dissolved in water?
You are confusing "polar" with "ionic". If a molecule has an electric dipole, then it can dissolve in a polar liquid. If a molecule can dissociate into ions, then it can dissolve in a polar liquid. However, not all molecules with an electric dipole can dissociate into ions. Acetic acid happens to be able to do both.So according to the rules of solubility all ionic compounds containing acetate are soluble in water. However acetic acid is a weak acid. Why is this if acetate is dissolved in water?
Only some of the H2COOH molecules will dissociate in water. When the molecule dissociates, in makes two H+ ions and one COO- ion. The number of H+ ions formed by dissociation determine whether a molecule is "acidic".
Yes, you are right. Thanks for pointing it out.I think you should double check yourself here. I'm not sure what molecule you're trying to denote but Acetic Acid (Ethanoic Acid) is CH3COOH and Formic Acid (Methanoic Acid) is HCOOH. Both are monoprotic acids.
Also acidity does not refer to the stoichiometric constants in the dissociation chemical equation but to the Keq/pKeq (or Ka/pKA because Chemists have to be difficult) of the dissociation chemical equation. The former being how I understood your post.
HX + H2O -> X- + H3O+ Keq = 10
H2X + 2H2O -> X2- + 2H3O+ This would happen in 2 steps but lets just say that the first step Keq_1 = 1/10 and the second lets say is the same Keq_2=1/10.
The strong acid is the first not the second even though the second yields two protons per dissociation while the first yields only 1. The degree of dissociation of the first is much higher than the second and therefore the first is the strong(er) acid.
Yes, you are right. Thanks for pointing it out.
My general argument is still correct. The CH3COOH has an electric dipole even before it dissociates. Therefore, it does not have to release hydrogen ions when it is dissolved in water. A few of the molecules do as determined by the pKa.
I am doomed !-)