![CHEM:ATOM FOC 2E CL (TEXT)](https://www.bartleby.com/isbn_cover_images/9780393284218/9780393284218_largeCoverImage.gif)
To find:
a) The
b) The suitable indicator for the titration referring figure 16.5
c) The
d) Sketch the titration curve
![Check Mark](/static/check-mark.png)
Answer to Problem 16.126QA
Solution:
a) The calculated
b) The suitable indicator for the titration, referring figure 16.5, is Alizarin Yellow R.
c) The
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
13)
14)
d) In the sketched titration curve
The major species at the equivalence point is
The major species at the end of titration is
Explanation of Solution
1) Concept:
To calculate the pH of a weak acid with a strong base, we need to use reaction stoichiometry and RICE table. First, we will calculate the equivalence point from the volume and molarity of base and acid. We will calculate the pH at equivalence point by using the RICE table. At the equivalence point, moles of phenol and
2) Formulae:
i)
ii)
iii)
iv)
3) Given:
i) Volume of phenol =
ii) Molarity of phenol
iii)
iv) Molarity of
4) Calculations:
a) Calculating
Step 1)
Finding the volume of
At the equivalence point, moles of phenol = moles of
At the equivalence point, moles of phenol and
Calculating the volume of
So, at the equivalence point, the volume of
So, the total volume of solution is
At the equivalence point, sodium salt of phenol is formed, and its moles will be equal to moles of phenol and
Calculating the molarity of sodium phenoxide:
Step 2)
Creating an RICE table for the dissociation of sodium phenoxide
RICE | |||
Initial (M) | |||
Change (M) | |||
Equilibrium (M) |
Writing the
The calculated
b) Choosing the indicator, which is suitable for the titration referring to figure 16.5:
A
c) Calculating the
The calculated volume of
1) Addition of 0.0 mL NaOH:
At 0.0mL NaOH added, the
RICE | |||
Initial (M) | |||
Change (M) | |||
Equilibrium (M) |
So, the
2) Addition of 2.5 mL NaOH:
Moles of phenol:
Moles of
We create a modified RICE table to determine how many moles of acid remain and how many moles of conjugate base have been produced:
Initial (mol) | |||
Change (mol) | |||
Final (mol) |
The total sample volume is
Applying the Henderson-Hasselbalch equation for the above buffer system formed as
3) Addition of 5.0 mL NaOH:
Moles of phenol:
Moles of
We create a modified RICE table to determine how many moles of acid remain and how many moles of conjugate base have been produced:
Initial (mol) | |||
Change (mol) | |||
Final (mol) |
The total sample volume is
Applying the Henderson-Hasselbalch equation for the above buffer system formed as
4) Addition of 7.5 mL NaOH:
Moles of phenol:
Moles of
We create a modified RICE table to determine how many moles of acid remains and how many moles of conjugate base have been produced.
Initial (mol) | |||
Change (mol) | |||
Final (mol) |
The total sample volume is
Applying the Henderson-Hasselbalch equation for the above buffer system formed as
5) Addition of 9.8 mL NaOH:
Moles of phenol:
Moles of
We create a modified RICE table to determine how many moles of acid remain and how many moles of conjugate base have been produced:
Initial (mol) | |||
Change (mol) | |||
Final (mol) |
The total sample volume is
Applying the Henderson-Hasselbalch equation for the above buffer system formed as
6) Addition of 10 mL NaOH:
Moles of phenol:
Moles of
We create a modified RICE table to determine how many moles of acid remain and how many moles of conjugate base have been produced:
Initial (mol) | |||
Change (mol) | |||
Final (mol) |
The total sample volume is
Applying the Henderson-Hasselbalch equation for the above buffer system formed as
7) Addition of 10.2 mL NaOH:
Moles of phenol:
Moles of
We create a modified RICE table to determine how many moles of acid remain and how many moles of conjugate base have been produced:
Initial (mol) | |||
Change (mol) | |||
Final (mol) |
The total sample volume is
Applying the Henderson-Hasselbalch equation for the above buffer system formed as
8) Addition of 10.6 mL NaOH:
The contribution of
Moles of
Initial (mol) | |||
Change (mol) | |||
Final (mol) |
Total volume of solution =
Molarity of
9) Addition of 10.8 mL NaOH
Moles of
Initial (mol) | |||
Change (mol) | |||
Final (mol) |
Total volume of solution =
Molarity of
10) Addition of 11 mL NaOH
Moles of
Initial (mol) | |||
Change (mol) | |||
Final (mol) |
Total volume of solution =
Molarity of
11) Addition of 12.5 mL NaOH
Moles of
Initial (mol) | |||
Change (mol) | |||
Final (mol) |
Total volume of solution =
Molarity of
12) Addition of 15 mL NaOH
Moles of
Initial (mol) | |||
Change (mol) | |||
Final (mol) |
Total volume of solution =
Molarity of
13) Addition of 17.5 mL NaOH:
Moles of
Initial (mol) | |||
Change (mol) | |||
Final (mol) |
Total volume of solution =
Molarity of
14) Addition of
Moles of
Initial (mol) | |||
Change (mol) | |||
Final (mol) |
Total volume of solution =
Molarity of
d) Graph of
The above curve is a plot of
The volume of
So, at half equivalence point, the major species would be
At the equivalence point, moles of acid initially present are equal to moles of added base. So, there will not be phenol or
At the end of the titration, the only major species present will be
Conclusion:
In the titration of a weak acid and strong base, the resultant salt formed is a basic salt. Hence, the
Want to see more full solutions like this?
Chapter 16 Solutions
CHEM:ATOM FOC 2E CL (TEXT)
- Nonearrow_forward4. Experimental Procedure. a. How many (total) data plots are to be completed for this experiment? Account for each. b. What information is to be extracted from each data plot?arrow_forwardProvide the IUPAC name of the following molecule. Don't forget to include the proper stereochemistry where appropriate.arrow_forward
- 3. 2. 1. On the graph below, plot the volume of rain in milliliters versus its height in centimeters for the 400 mL beaker. Draw a straight line through the points and label it "400 mL beaker." Volume (mL) 400 350 300 250 200 150 750 mL Florence Volume Versus Height of Water 400 mL beaker 100 50 0 0 2 3 4 5 Height (cm) 6 7 8 9 10 Explain why the data points for the beaker lie roughly on a straight line. What kind of relationship is this? How do you know? (see page 276 text) the design of the beaker is a uniform cylinder the volume of liquid increases evenly with its height resulting in a linear relationship. What volume would you predict for 10.0 cm of water? Explain how you arrived at your answer. Use the data table and the graph to assist you in answering the question. 4. Plot the volume of rain in milliliters versus its height in centimeters for the 250 mL Florence flask on the same graph. Draw a best-fit curve through the points and label it "250 mL Florence flask." oke camearrow_forwardShow work. Don't give Ai generated solutionarrow_forwardIn the video, we looked at the absorbance of a certain substance and how it varies depending on what wavelength of light we are looking at. Below is a similar scan of a different substance. What color BEST describes how this substance will appear? Absorbance (AU) Violet Blue Green Orange 1.2 1.0- 0.8- 0.6- 0.4- 0.2 0.0 450 500 550 600 650 700 Wavelength (nm) violet indigo blue green yellow orange red Red O Cannot tell from this information In the above graph, what causes -450 nm wavelength of light to have a higher absorbance than light with a -550 nm wavelength? Check all that are true. The distance the light travels is different The different data points are for different substances The concentration is different at different times in the experiment Epsilon (molar absortivity) is different at different wavelengthsarrow_forward
- 5. a. Data were collected for Trial 1 to determine the molar mass of a nonvolatile solid solute when dissolved in cyclo- hexane. Complete the table for the analysis (See Report Sheet). Record calculated values with the correct number of significant figures. B. Freezing Point of Cyclohexane plus Calculation Zone Unknown Solute 2. Mass of cyclohexane (g) 10.14 Part C.4 3. Mass of added solute (g) 0.255 C. Calculations 1. k; for cyclohexane (°C⚫ kg/mol) 20.0 2. Freezing point change, AT, (°C) 3.04 Part C.6 3. Mass of cyclohexane in solution (kg) 4. Moles of solute, total (mol) Show calculation. 5. Mass of solute in solution, total (g) 6. Molar mass of solute (g/mol) Show calculation.arrow_forwardDraw and name the R groups of all 20 amino acids.arrow_forward3. Two solutions are prepared using the same solute: Solution A: 0.14 g of the solute dissolves in 15.4 g of t-butanol Solution B: 0.17 g of the solute dissolves in 12.7 g of cyclohexane Which solution has the greatest freezing point change? Show calculations and explain.arrow_forward
- ChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage LearningChemistryChemistryISBN:9781259911156Author:Raymond Chang Dr., Jason Overby ProfessorPublisher:McGraw-Hill EducationPrinciples of Instrumental AnalysisChemistryISBN:9781305577213Author:Douglas A. Skoog, F. James Holler, Stanley R. CrouchPublisher:Cengage Learning
- Organic ChemistryChemistryISBN:9780078021558Author:Janice Gorzynski Smith Dr.Publisher:McGraw-Hill EducationChemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher:Cengage LearningElementary Principles of Chemical Processes, Bind...ChemistryISBN:9781118431221Author:Richard M. Felder, Ronald W. Rousseau, Lisa G. BullardPublisher:WILEY
![Text book image](https://www.bartleby.com/isbn_cover_images/9781305957404/9781305957404_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781259911156/9781259911156_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781305577213/9781305577213_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9780078021558/9780078021558_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781305079373/9781305079373_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781118431221/9781118431221_smallCoverImage.gif)