[SOLVED] pH Change

Part I: pH change of an unbuffered solution 1.Load http://chemcollective.org/vlab/1022.Add a 250 mL beaker to your workspacefrom the stockroom.3.Add 10 mL of the protein solution.  (To add something to a beaker drag the solution on top of it until the prompt appears.)Then add 90 ml of water to the solution.Record the pH:_____________________(you find the pH by clicking on the beaker)4.To the same beaker under strong acids add 10 mL  0.10 M HClfrom the stockroom strong acid solutions. Record the pH: _____________________ (you find the pH by clicking on the beaker)5.What is the change in pH?_______________________________Part II: pH change of a buffered solution1.You have available the following:100.0mL of 1.0 MH2CO3 (weak acid; pKa= 6.4)100.0mL of 1.0 MNaHCO3(conjugatebase of H2CO3; but also a weak acidpKa=10.3)100.0 mL of Grey Goose Vodka100.0mL of 1.0 MNa2CO3(conjugate base of HCO3-)First, explain whichof the solutions aboveyou would useto make a 1 M Carbonate buffer at pH=6.0Next describe how much of each solution you would useto make a 1 M Carbonate buffer at pH=6.0and indicate the total volume.  Show any calculations2.Reload the Virtual lab page and create your buffer solution above.  Was your math correct? Record the pH:______________________ Acceptable ranges are +/-0.05 pH units3.Add another beaker to your workspace and add 10 mL of the protein solution. Then add 90 ml of buffer to the solution.Record the pH___________________4.To the same beaker add 10 mL  0.10 M HClfrom the stockroom strong acid solutions. Record the pH: _____________________ (you find the pH by clicking on the beaker)5.What is the change in pH?_______________________________Post lab questions1.In Part II, if instead of making a 1.00M carbonate solution, you made 0.100 M carbonate solution, how would this effect the change in pHwhen you added 0.1 M HCl to the protein buffer solution? What would be the new pH?  Show your calculations and also use the program. Compare the two results.2.If you wanted to make a buffer at pH=8.  Would carbonate be a suitable buffer?  Please explain why or why not?3.Why is it important thatbiochemistry solutions are in buffered solutions?