Post lab Questions: 1. According to your graphed data is one buffer (beaker 1-3)
ID: 1021926 • Letter: P
Question
Post lab Questions:
1. According to your graphed data is one buffer (beaker 1-3) better or worse than the other(s)? Explain.
2. Write out the chemical reaction that occurs in the Acetic Acid / Acetate buffer when a. NaOH is added b. HCl is added
3. Write out the chemical reaction that occurs in the Ammonia/Ammonium buffer when a. NaOH is added b. HCl is added
5. Does distilled water make a good buffer? Why or why not?
6. How can you tell if the buffer is working?
7. What happens when you go beyond the buffer capacity? How is buffer capacity indicated on your graph(s)?
Explanation / Answer
1) beaker 1 is the best and beaker 3 contains worse buffer solution because the change in the beaker 1 is the least due to addition of NaOH which leads to higher buffer capacity
2) a) CH3COOH + NaOH -----------> CH3COO- + H2O
B) CH3COO- + HCl --------------> CH3COOH + Cl-
3) A) NH4+ + OH- ------------> NH3 + H2O
b) NH3 + HCl ------------> NH4+ + Cl-
4) A) no reaction
b) no reaction
5) No because it is not a solution of weak acid and its conjugate base.
6) if the change in pH on addition of base or acid is very less,then we can say that buffer has a good capacity.
7) beyond the buffer capacity, the ph changes very fast and in the graph buffer capacity is indicated as the region where slope is almost zero