Your report form for this experiment will include 3 attached Excel spreadsheets (each one on a separate 8.5”x11” sheet of paper). Each spreadsheet MUST INCLUDE (i) the titration data (ii) the titration curve graph and (iii) a data box.

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102 Exercise 7 Report Form:  Acids and Bases – Titration Curves (Part 1)

 

Your report form for this experiment will include 3 attached Excel spreadsheets (each one on a separate 8.5”x11” sheet of paper).  Each spreadsheet MUST INCLUDE (i) the titration data (ii) the titration curve graph and (iii) a data box.

 

(3 points) For acetic acid:

(i)  The titration curve data in two columns.

(ii)  The graph of pH versus volume of titrant.

(iii)  In the data box include the value of pKa as determined from the pH halfway to the equivalence point and the molarity of the acetic acid using 0.075 M NaOH for the titrant and the volume of titrant used at the observed equivalence point.  An example is given below (note the values are examples only):

 

Data Box

 

Equivalence point (mL titrant)

12.50

Half equivalence point (mL titrant)

6.25

Half equivalence point pH

4.34

pKa

4.34

Original molarity of acetic acid (mol/L)

0.094

 

(3 points) For phosphoric acid:

(i)  The titration curve data in two columns.

(ii)  The graph of pH versus volume of titrant.

(iii)  In the data box include the values of pKal and pKa2 as determined from the pH halfway to the relevant equivalence points, and the molarity of the phosphoric acid using 0.075 M NaOH for the titrant and the volume of titrant used at the observed equivalence points.  An example is given below (note the values are examples only):

 

Data Box

 

Equivalence point 1 (mL titrant)

10.00

Equivalence point 2 (mL titrant)

20.00

Half equivalence point 1 pH

4.89

Half equivalence point 2 pH

8.90

pKa1

4.89

pKa2

8.90

Molarity of phosphoric acid (mol/L)

0.082

 

(3 points) For the unknown acid:

(i)  The titration curve data in two columns.

(ii)  The graph of pH versus volume of titrant.

(iii)  In the data box include the value of pKa for the weak acid, the molarity of the weak acid and your guess of the identity of the weak acid.  Possible unknown weak acids from which to choose from are:

 

 

Ka

Acetylsalicylic acid

3.3x10-4

Lactic acid

1.4x10-4

Benzoic acid

6.5x10-5

Potassium hydrogen phthalate

3.9x10-6

Hydrogen chromate ion

3.0x10-7

Phenol

1.3x10-10

 

Below is an example of the data box (note the values are examples only):

 

Data Box

 

Unknown number

1234

Equivalence point (mL titrant)

10.67

Original molarity of the unknown acid (mol/L)

0.103

Estimated pKa

6.54

Identity of the unknown acid

Phenol

Instruction Files

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