Strong Acid Titration | Summary and Q&A

TL;DR

In an acid-base titration, adding a strong base to a strong acid gradually increases the pH until reaching the equivalence point at pH 7.

Key Insights

• 😥 Strong acids, like hydrochloric acid, dissociate completely in water, resulting in a pH of 0.
• 😥 By titrating a strong acid with a strong base, the pH gradually increases until reaching the equivalence point at pH 7.
• 😐 The equivalence point in an acid-base titration occurs when the hydroxide concentration equals the hydrogen concentration, leading to a completely neutral solution.

Transcript

Let's have 1 molar of-- let me pick a strong acid. Let's say it's hydrochloric acid. HCl. And we know, of course, that since it's a strong acid it disassociates completely. So HCl in an aqueous solution-- or a solution of water-- disassociates completely into hydrogen ions in an aqueous solution, which is really hydronium. I've said that multiple t... Read More

Questions & Answers

Q: What happens when hydrochloric acid is dissolved in water?

When hydrochloric acid is dissolved in water, it completely dissociates into hydrogen ions (hydronium) and chlorine anions, resulting in a hydrogen concentration of 1 molar and a pH of 0.

Q: What is the purpose of acid-base titration?

Acid-base titration is used to determine the concentration of an acid or base by gradually adding a known concentration of the opposite reactant until reaching the equivalence point, where the number of moles of acid and base are equal.

Q: How does the pH change during the titration process?

As a strong base is added to the strong acid, the hydroxide ions react with the hydrogen ions, reducing their concentration. Since pH is the negative logarithm of the hydrogen concentration, the pH gradually increases until reaching the equivalence point at pH 7.

Q: How can the equivalence point be determined in an acid-base titration?

The equivalence point is determined by analyzing the titration curve and identifying the steepest point, which indicates the transition from an excess of hydrogen ions to an excess of hydroxide ions. At the equivalence point, the hydroxide concentration equals the hydrogen concentration, resulting in a pH of 7.

Summary & Key Takeaways

• A strong acid, such as hydrochloric acid, completely dissociates in water, resulting in 1 molar hydrogen concentration and a pH of 0.

• By titrating the acid with a strong base, like sodium hydroxide, the pH gradually increases due to the reaction between hydroxide ions and hydrogen ions. The equivalence point occurs when the hydroxide concentration is equal to the hydrogen concentration, resulting in a pH of 7.