Potentiometric Titration of Strong Acid with Strong Base
15 Questions
4 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the main purpose of potentiometric titration?

  • To classify different types of titrations based on their methods
  • To determine the concentration of an unknown analyte without using a chemical indicator (correct)
  • To measure the pH of a solution using a chemical indicator
  • To detect the presence of unsuspected species in a solution
  • What does pH measure in a solution?

  • The concentration of hydroxide ions
  • The negative logarithm of the activity of hydrogen ions
  • The activity of oxygen ions
  • The concentration of hydrogen ions (correct)
  • Why is potentiometric titration considered more reliable than titrations using chemical indicators?

  • It can be used with colored or turbid solutions
  • It measures the electric potential across the substance
  • It does not rely on visual color changes in the solution (correct)
  • It can detect the presence of unsuspected species
  • What is the volume of NaOH used at the end point in the procedure?

    <p>The volume at which the solution changes to pink</p> Signup and view all the answers

    What type of titration is potentiometric titration classified as?

    <p>Acid-base titrations (neutralization titrations)</p> Signup and view all the answers

    What is the purpose of washing the electrode with D. W. and drying it before immersing it in the buffer solutions?

    <p>To ensure accurate pH measurements by removing any impurities on the electrode surface</p> Signup and view all the answers

    In the titration process, why is it important to add smaller volumes of NaOH towards the equivalence point?

    <p>To achieve a more precise determination of the equivalence point</p> Signup and view all the answers

    Why is the shape of the graph between pH and volumes of NaOH typically like shape (A)?

    <p>It represents the characteristic S-shaped curve of a titration involving a strong acid and a strong base</p> Signup and view all the answers

    What is the main reason behind considering HCl a strong acid?

    <p>HCl dissociates completely into ions in aqueous solution</p> Signup and view all the answers

    Why is it important to record the values of pH for the mixture in the beaker after each addition of NaOH during titration?

    <p>To monitor the progress of the reaction and identify the equivalence point</p> Signup and view all the answers

    What is the purpose of immersing the electrode in buffer solutions with pH 4 and pH 9 before recording the pH value of the HCl solution?

    <p>To calibrate the pH meter and ensure accurate pH measurements</p> Signup and view all the answers

    Why is it recommended to add larger volumes of NaOH towards the end of the titration, just before the pH stops rising markedly?

    <p>To accurately determine the endpoint of the titration</p> Signup and view all the answers

    What does the plot of pH against volumes of NaOH look like during the titration process according to the text?

    <p>An initial increase, then a plateau, and finally a steep increase</p> Signup and view all the answers

    Why is HCl considered a strong acid?

    <p>It completely dissociates into ions in solution</p> Signup and view all the answers

    How can the molarity of the HCl solution be calculated from the titration data?

    <p>By finding the volume of NaOH at the equivalence point</p> Signup and view all the answers

    Study Notes

    Potentiometric Titration

    • The main purpose of potentiometric titration is to determine the concentration of a solution (e.g., HCl) by measuring the potential (voltage) of a reaction between the solution and a titrant (e.g., NaOH).
    • pH measures the concentration of hydrogen ions (H+) in a solution.

    Advantages of Potentiometric Titration

    • Potentiometric titration is considered more reliable than titrations using chemical indicators because it provides a more accurate and precise measurement of the endpoint.

    Titration Procedure

    • The volume of NaOH used at the end point is the volume at which the pH of the solution sharply increases, indicating the equivalence point.
    • Potentiometric titration is classified as a type of volumetric titration.

    Electrode Preparation

    • The electrode should be washed with distilled water (D.W.) and dried before immersing it in the buffer solutions to ensure accurate pH measurements.

    Titration Process

    • Smaller volumes of NaOH should be added towards the equivalence point to accurately determine the endpoint.
    • The graph of pH against volumes of NaOH typically has an S-shape (A) due to the rapid change in pH at the equivalence point.

    Acid-Base Properties

    • HCl is considered a strong acid because it completely dissociates in water, resulting in a high concentration of hydrogen ions (H+).

    pH Measurement

    • Recording the pH values of the mixture after each addition of NaOH during titration is important to track the progress of the reaction and determine the endpoint.
    • The electrode should be calibrated by immersing it in buffer solutions with pH 4 and pH 9 before recording the pH value of the HCl solution to ensure accurate pH measurements.

    Titration Data Analysis

    • The plot of pH against volumes of NaOH during the titration process typically shows a sharp increase in pH at the equivalence point.
    • The molarity of the HCl solution can be calculated from the titration data by using the volume of NaOH at the equivalence point and the stoichiometry of the reaction.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    Learn about the laboratory method of potentiometric titration to determine the concentration of an unknown analyte without using a chemical indicator. Understand how pH or electric potential measurements are used to determine the equivalent point in the process.

    More Like This

    Use Quizgecko on...
    Browser
    Browser