Name: _________________________________________
Date:____________________________
Optional Homework
1.) 1.) Given the following information: Ka for acetic acid = 1.8 x 10-5. Calculate the pH if 0.08
M H3O+1 is added to an acetic acid buffer system that is 1.252 M acetic acid and 1.232 M
sodium acetate. (please solve using the ICE table method, you can check your answer using
Henderson-Hasselbalch if you would like!)
2.) A buffer solution is prepared that is 0.44 M NH3 and 0.40 M NH4Cl.
a. What is the pH of this buffer system if the Kb for ammonia = 1.8 x 10-5?
b. If 0.0050 moles of NaOH is added to 0.500 L of solution, what will the new pH be?
(again, please solve using the ICE table method and if you would like to check your
answer using Henderson-Haseelbalch you can!)
3.) If you want a buffer system which will work at the following pH, list possible buffer systems
(remember to list them correctly!!!)
a. pH = 3.5
b. pH = 9.2
4.) An environmental chemist needs a carbonate buffer of pH = 10.00 to study the effects of acid rain on
soil. What molarity of Na2CO3 is needed to make the buffer have a pH of exactly 10.00? How many
grams of Na2CO3 must be added to 1.50 L of freshly prepared 0.200 M NaHCO3 in order to make the
buffer have a pH of 10.00?
5.) If the concentration of benzoic acid is 1.10 M, what concentration of benzoate would you need for a
benzoic acid/benzoate buffer so that the pH = 4.5