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cp255
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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.cp255 said: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?
Darwin123 said: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.Yanick said: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.
IE:
HX + H2O -> X- + H3O+ Keq = 10
H2X + 2H2O -> X2- + 2H3O+ This would happen in 2 steps but let's just say that the first step Keq_1 = 1/10 and the second let's 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.
Darwin123 said: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 !-)
Acetic acid is a weak organic acid with the chemical formula CH3COOH. It is a clear, colorless liquid with a distinctive sour taste and pungent smell. It is commonly known as the main component of vinegar.
Acetic acid is considered weak because it does not completely dissociate in water. This means that only a small portion of acetic acid molecules break apart into ions, resulting in a low concentration of hydrogen ions. As a result, acetic acid has a relatively low acidity compared to strong acids like hydrochloric acid or sulfuric acid.
The strength of an acid is determined by its tendency to donate a proton (H+) to a water molecule. Strong acids have a high tendency to donate protons, resulting in almost complete dissociation in water. Weak acids, on the other hand, have a lower tendency to donate protons and therefore do not fully dissociate in water.
The strength of acetic acid can be affected by several factors, including its concentration, temperature, and the presence of other substances. Higher concentrations of acetic acid will result in a stronger acid, while lower concentrations will result in a weaker acid. Higher temperatures can also increase the rate of dissociation, making the acid stronger. Additionally, the presence of other substances, such as salts or weak bases, can also affect the strength of acetic acid.
The weak acidity of acetic acid makes it suitable for a variety of uses. It is commonly used in food production as a preservative and flavoring agent. It is also used in household cleaning products, as well as in the production of plastics, textiles, and pharmaceuticals. The weak nature of acetic acid also makes it safe for human consumption in small amounts, such as in vinegar for cooking.