Lab 14/ Test 6: Determination of Acid Dissociation Constants through Titration
Sabrina Tom
I.Abstract The two unknown solutions A and E were titrated with NaOH solutions. For each solution, one fast and three slow titrations were done to see where the pH rose exponentially. The unknown solutions A and E were determined to be Pyridinium ion acid and oxalic acid, respectively.
II.Theories One significant concept throughout this lab is titrations. A titration is a lab method analyzes a solution of a known concentration to determine the concentration of a known solution. The solution of the known concentration (also called the titrant) is slowly added from the buret to the beaker containing the unknown solution. The addition of the known …show more content…
CONCLUSION
To find the unknown solutions, I compared the calculated pKa’s to the pKa’s of acids listed on this website: http://clas.sa.ucsb.edu/staff/Resource%20Folder/Chem109ABC/Acid,%20Base%20Strength/Table%20of%20Acids%20w%20Kas%20and%20pKas.pdf . Pyridinium ion acid had the closest pKa (5.25) to solution A (5.16) and oxalic acid (4.19) had the closest to unknown E(4.39).
The Ve = 50 mL because (50 x 0.05)/ 0.05= 50.
At Vb=0, pH = 3.28 because Ka = x^2 / (.5-x) and
Sabrina Tom
I.Abstract The two unknown solutions A and E were titrated with NaOH solutions. For each solution, one fast and three slow titrations were done to see where the pH rose exponentially. The unknown solutions A and E were determined to be Pyridinium ion acid and oxalic acid, respectively.
II.Theories One significant concept throughout this lab is titrations. A titration is a lab method analyzes a solution of a known concentration to determine the concentration of a known solution. The solution of the known concentration (also called the titrant) is slowly added from the buret to the beaker containing the unknown solution. The addition of the known …show more content…
CONCLUSION
To find the unknown solutions, I compared the calculated pKa’s to the pKa’s of acids listed on this website: http://clas.sa.ucsb.edu/staff/Resource%20Folder/Chem109ABC/Acid,%20Base%20Strength/Table%20of%20Acids%20w%20Kas%20and%20pKas.pdf . Pyridinium ion acid had the closest pKa (5.25) to solution A (5.16) and oxalic acid (4.19) had the closest to unknown E(4.39).
The Ve = 50 mL because (50 x 0.05)/ 0.05= 50.
At Vb=0, pH = 3.28 because Ka = x^2 / (.5-x) and