You found a bottle of aqueous solution in the laboratory cabinet. Unfortunately, the label has been eroded and you could not recognize it. To the best of your recollection, it may be one of the following solutions:   HCl   CH3COOH   CH3CH2COOH   A mixture of HF and NaF (both of substantial amount)   A mixture of H3PO4 and NaH2PO4 (both of substantial amount)   NH4Cl   NaHCO3

General Chemistry - Standalone book (MindTap Course List)
11th Edition
ISBN:9781305580343
Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; Darrell
Publisher:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; Darrell
Chapter16: Acid-base Equilibria
Section: Chapter Questions
Problem 16.157QP: Weak base B has a pKb of 6.78 and weak acid HA has a pKa of 5.12. a Which is the stronger base, B or...
icon
Related questions
icon
Concept explainers
Question

You found a bottle of aqueous solution in the laboratory cabinet. Unfortunately, the label has been eroded and you could not recognize it. To the best of your recollection, it may be one of the following solutions:

  •   HCl

  •   CH3COOH

  •   CH3CH2COOH

  •   A mixture of HF and NaF (both of substantial amount)

  •   A mixture of H3PO4 and NaH2PO4 (both of substantial amount)

  •   NH4Cl

  •   NaHCO3

    In order to identify the solution, you conduct the following experiments:

    1. Using a pH meter, you determine the pH of the solution to be 3.00.

    2. You dilute 20 mL of the solution with water to a total volume of 200 mL and

      measure the pH again, this time it reads 3.50.

    3. You take some volume of the solution, add phenolphthalein, and titrate it with

      NaOH solution until the mixture turns pink. You record the volume of the required titrant as Vt and the pH meter reads 9.05.

    4. In a separate flask, you take the same volume of the unknown solution as in step iii and titrate it with the same NaOH solution, but this time only add half of the volume Vt/2. The mixture remains colorless and the pH meter reads 4.87.

       

      b/ The volume of the unknown solution you took in steps iii and iv was 20.00 mL. The concentration of the NaOH solution was 0.04587 M and Vt = 32.98 mL. Calculate the concentration(s) of the unknown species.

       

Expert Solution
Step 1 titration method

                           Answer 

   Identity unknown compounds

trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps

Blurred answer
Knowledge Booster
Ionic Equilibrium
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
General Chemistry - Standalone book (MindTap Cour…
General Chemistry - Standalone book (MindTap Cour…
Chemistry
ISBN:
9781305580343
Author:
Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; Darrell
Publisher:
Cengage Learning
Chemistry: An Atoms First Approach
Chemistry: An Atoms First Approach
Chemistry
ISBN:
9781305079243
Author:
Steven S. Zumdahl, Susan A. Zumdahl
Publisher:
Cengage Learning
Chemistry
Chemistry
Chemistry
ISBN:
9781305957404
Author:
Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning
Chemistry
Chemistry
Chemistry
ISBN:
9781133611097
Author:
Steven S. Zumdahl
Publisher:
Cengage Learning
Chemistry & Chemical Reactivity
Chemistry & Chemical Reactivity
Chemistry
ISBN:
9781337399074
Author:
John C. Kotz, Paul M. Treichel, John Townsend, David Treichel
Publisher:
Cengage Learning
Chemistry & Chemical Reactivity
Chemistry & Chemical Reactivity
Chemistry
ISBN:
9781133949640
Author:
John C. Kotz, Paul M. Treichel, John Townsend, David Treichel
Publisher:
Cengage Learning