prepare 25 mL 0.40M sodium acetate-acetic acid buffer solution at a pH of 4.40 (pka 4.74).
Posted: Tue Jul 12, 2022 1:08 pm
prepare 25 mL 0.40M sodium acetate-acetic acid buffer solution at a pH of 4.40 (pka 4.74).
- NOTE: You will be provided with a 3.0M Acetic acid stock solution and Solid Sodium Acetate (MW 82.03 g/mol ) with which to make the buffer. Please complete the calculations needed to prepare the buffer PRIOR to coming to lab. - Sodium Acetate is a solid that should be weighed to the nearest 0.001 g, while Acetate acid is a liquid on a solution with a molar concentration - From this buffer solution, take 10 mL, measure its pH, then begin a titration process as described previously with NaOH0.3M. - Measure the pH every 0.5 mL and remember to stir the solution and record the new pH every time you add the titrant. - Record the pH until the buffer pH changes by 1pH unit. - Repeat the process with another 10 mL solution of buffer, using 0.3MHCl as titrant. - Record the pH until the buffer pH changes by 1pH unit. - Take the remaining 5 mL of prepared buffer and dilute with 20 mL of DI water using your 25 mL volumetric. ( 1:5 dilution) - From this solution, take 10 mL, measure its pH, then begin a titration process as described previously with NaOH0.3M. Measure the pH every 0.5 mL and remember to stir the solution and record the new pH every time you add the titrant.
- NOTE: You will be provided with a 3.0M Acetic acid stock solution and Solid Sodium Acetate (MW 82.03 g/mol ) with which to make the buffer. Please complete the calculations needed to prepare the buffer PRIOR to coming to lab. - Sodium Acetate is a solid that should be weighed to the nearest 0.001 g, while Acetate acid is a liquid on a solution with a molar concentration - From this buffer solution, take 10 mL, measure its pH, then begin a titration process as described previously with NaOH0.3M. - Measure the pH every 0.5 mL and remember to stir the solution and record the new pH every time you add the titrant. - Record the pH until the buffer pH changes by 1pH unit. - Repeat the process with another 10 mL solution of buffer, using 0.3MHCl as titrant. - Record the pH until the buffer pH changes by 1pH unit. - Take the remaining 5 mL of prepared buffer and dilute with 20 mL of DI water using your 25 mL volumetric. ( 1:5 dilution) - From this solution, take 10 mL, measure its pH, then begin a titration process as described previously with NaOH0.3M. Measure the pH every 0.5 mL and remember to stir the solution and record the new pH every time you add the titrant.