University of Washington CHEM 152 lab 2_Buffers Report Complete -Graded A

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Deprotonation of Acetic Acid 3 pt rxn, 2 pt for Ka, 2 pt for Kb (correct & entered) Provide the acid dissociation reaction for proton removal in water: Provide the Ka value for the acid 1.8E-05 D... ATA AND CALCULATIONS Parts A - D: Preparation of Acetic Acid/Acetate Solutions 5 pts: ALL solution prep data and expected initial pH values entered Molarity of Stock Soln (M) CH3COOH 0.1M Molar Mass Mass of Solid Moles of Solid Volume of Water *Molarity (g/mol) Used (g) (mol) (mL) (M) CH3COONa·3H2O 136.08 g/mol 1.361g 0.01 mol 100mL 0.1M *(from calculation on pg 2) Solution ID mL of CH3COOH mL of CH3COONa mL Water Total Volume *Summary of Expected Initial pH #1 20.00mL 0.00mL 30.00mL 50.00mL 3.07 *(based on example #2 15.00mL 5.00mL 30.00mL 50.00mL 4.27 calculations on pg 2) #3 10.00mL 10.00mL 30.00mL 50.00mL 4.74 #4 5.00mL 15.00mL 30.00mL 50.00mL 5.22 #5 0.00mL 20.00mL 30.00mL 50.00mL 8.67 DI Water -- -- 50.00mL 50.00mL 7.00 Part E: Preparation of Aspirin and Buffered Aspirin Solutions Mass of Solid (for acid test) Mass of Solid (for base test) (g) (g) Aspirin 0.218g 0.214g Molarity of HCl for acid test: 0.5M Molarity of NaOH for base test: 0.5M Buffered Aspirin 0.433g 0.431g Volume (mL) of HCl added: 0.25mL Volume (mL) of NaOH added: 0.25mL Millimoles of HCl added: 0.125mmol Millimoles of NaOH added: 0.125mmol Parts C-E: pH Measurements and Determi [Show More]

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