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36 votes
36 votes
Hydrochloric acid in the stomach is a very strong acid compared

to ethanoic acid that is found in citrus fruits. Explain (with
reference to formation of hydronium ions) why hydrochloric acid
has a much lower pH compared to ethanoic acid. You should
support this answer with accompanying ionic equations.

User Samuel James
by
3.3k points

1 Answer

15 votes
15 votes

Answer:

Explanation:Hydrochloric acid (HCl) in the stomach is a much stronger acid than ethanoic acid (also known as acetic acid) found in citrus fruits. The strength of an acid is determined by its ability to donate protons (H+ ions) to a solution, and the concentration of H+ ions in a solution determines its pH. A solution with a higher concentration of H+ ions will have a lower pH, while a solution with a lower concentration of H+ ions will have a higher pH.

When hydrochloric acid is dissolved in water, it ionizes to form hydronium ions (H3O+) and chloride ions (Cl-). This process can be represented by the following ionic equation:

HCl + H2O → H3O+ + Cl-

The hydronium ions that are formed in this reaction are responsible for the acidity of the solution. The concentration of hydronium ions in a solution of hydrochloric acid is much higher than the concentration of H+ ions in a solution of ethanoic acid, which means that hydrochloric acid has a much lower pH compared to ethanoic acid.

The ionization of ethanoic acid in water is a similar process, but it results in the formation of fewer H+ ions compared to hydrochloric acid. This is because ethanoic acid is a weaker acid than hydrochloric acid, and it donates fewer protons to the solution. The ionic equation for the ionization of ethanoic acid in water is as follows:

CH3COOH + H2O → CH3COO- + H3O+

As you can see, the ionization of ethanoic acid results in the formation of one H3O+ ion for every molecule of acid that ionizes. In comparison, the ionization of hydrochloric acid results in the formation of one H3O+ ion for every molecule of acid that ionizes, plus an additional H+ ion. This means that the concentration of H+ ions in a solution of hydrochloric acid is much higher than the concentration of H+ ions in a solution of ethanoic acid, which leads to a much lower pH for hydrochloric acid compared to ethanoic acid.

I hope this helps to explain the difference in pH between hydrochloric acid and ethanoic acid. Let me know if you have any other questions.

User Hossam Fathy
by
2.9k points