Questions: Which acid/base pair will give an equivalence point above a pH of 7? Select the correct answer below: NaOH and HCl NH3 and HCl NH3 and CH3COOH NaOH and CH3COOH

Which acid/base pair will give an equivalence point above a pH of 7?

Select the correct answer below:
NaOH and HCl
NH3 and HCl
NH3 and CH3COOH
NaOH and CH3COOH

Transcript text: knewton.com Unit 6.3 - Buffers - Knewton Unit 6.4 - Titrations | Knewton CURRENT OBJECTIVE Interpret titration curves First up, let's review the assignment's learning objectives Get familiar with this topic by reviewing instruction and answering a couple of questions. Question Which acid/base pair will give an equivalence point above a pH of 7 ? Select the correct answer below: NaOH and HCl $\mathrm{NH}_{3}$ and HCl $\mathrm{NH}_{3}$ and $\mathrm{CH}_{3} \mathrm{COOH}$ NaOH and $\mathrm{CH}_{3} \mathrm{COOH}$

Solution

Solution Steps

Step 1: Understand the Concept of Equivalence Point

The equivalence point in a titration is where the amount of acid equals the amount of base. For strong acid-strong base titrations, the equivalence point is typically at pH 7. For weak acid-strong base titrations, the equivalence point is above pH 7 because the conjugate base of the weak acid will hydrolyze to form OH$^-$ ions, making the solution basic.

Step 2: Analyze Each Acid/Base Pair

NaOH and HCl: Both are strong, so the equivalence point will be at pH 7.
NH$_3$ and HCl: NH$_3$ is a weak base and HCl is a strong acid, so the equivalence point will be below pH 7.
NH$_3$ and CH$_3$COOH: NH$_3$ is a weak base and CH$_3$COOH is a weak acid. The equivalence point will depend on the relative strengths of the weak acid and weak base, but it is typically around pH 7.
NaOH and CH$_3$COOH: NaOH is a strong base and CH$_3$COOH is a weak acid, so the equivalence point will be above pH 7.

Step 3: Select the Correct Answer

Based on the analysis, the pair that will give an equivalence point above a pH of 7 is NaOH and CH$_3$COOH.