Why does the OH react with HA and not H3O+?

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However, in titrating HA with a strong base, the OH- ions preferentially react with the HA molecule to neutralize it rather than with the H3O+ ions, resulting in complete neutralization. This is because the hydroxide ions are more likely to interact with the weak acid molecules, ultimately favoring the neutralization of HA over the formation of hydronium ions. In summary, in titrating HA, the OH- ions from the strong base react with the HA atom to neutralize it due to their preference for interacting with weak acid molecules.
  • #1
motornoob101
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In titrating HA, the weak acid with a strong base, why does the OH- ions from the strong base react with the HA atom (and neutralize it) rather than say react with the H3O+ to form complete neutralization? Just curious. Thanks.
 
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  • #2
HA donates protons to water regardless of whether the base is present or not however the hydroxide can neutralize the remaining HA molecules. Ultimately hydroxide is going to prefer the latter over the former.
 
  • #3
motornoob101 said:
In titrating HA, the weak acid with a strong base, why does the OH- ions from the strong base react with the HA atom (and neutralize it) rather than say react with the H3O+ to form complete neutralization? Just curious.
Thanks.

Hydroxide deprotonates weak acids and hydronium ion alike. In a basic solution, hydroxide abstracts acidic protons from both molecules.
 

1. Why does the OH react with HA and not H3O+?

The reaction of OH with HA is a neutralization reaction, in which the OH^- ion receives a proton from the HA molecule to form water (H2O). This reaction occurs because the OH^- ion acts as a strong base, while the H3O+ ion is a weak acid. Therefore, the OH^- ion is more likely to react with the HA molecule to form water.

2. How does the strength of OH and HA affect their reactivity?

The strength of a base or an acid is determined by its ability to donate or accept protons. In the case of OH and HA, the OH^- ion is a stronger base than the H3O+ ion, and the HA molecule is a stronger acid than water. This difference in strength affects their reactivity, making the OH^- ion more likely to react with the HA molecule to form water.

3. What is the role of electronegativity in the reaction of OH with HA?

Electronegativity is the measure of an atom's ability to attract electrons towards itself. In the OH and HA reaction, the OH^- ion has a higher electronegativity than the H3O+ ion. This means that the OH^- ion has a greater affinity for electrons, making it a stronger base and more likely to react with the HA molecule to form water.

4. Can the OH^- ion react with other molecules besides HA?

Yes, the OH^- ion can react with other molecules besides HA. The OH^- ion is a strong base and can react with any molecule that has a proton to donate. However, the strength of the OH^- ion's reactivity will depend on the strength of the other molecule's acidity.

5. How does the reaction of OH with HA affect the pH of a solution?

The reaction of OH with HA results in the formation of water, which is a neutral molecule. This means that the concentration of H3O+ ions in the solution decreases, leading to a decrease in the solution's acidity. Therefore, the pH of the solution increases, becoming more basic.

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