CHEM 4400 Fall
Ka for KOH
is very large
What is the pH of 500 mL of a 0.015 M solution of KOH?
is the pH of a solution made by adding 25 ml of 2.0M HCl
to 475 mL of water.
is the pH of a 0.02 M solution of acetic acid?
Draw the titration curve for the titration of a 0.05 M solution of acetic acid
with 0.1 M sodium hydroxide.
Draw the titration curve for the titration of 0.1M glycine with 0.1M sodium
hydroxide. Glycine has a pKa of
2.35 for the carboxylic acid group and a pKa of 9.78 for the amino group.
The complete structure is in your book.
and the Vampire slayers:
You need to make a buffer for your biochemistry laboratory experiment
that involves intestinal mucosa cells. These
cells require a pH of 6.7 to survive. Give
the complete directions (including
substances, volumes and weights) for preparing 500 mL of this 0.2M buffer
solution. The following Ka values
may be useful:
H3PO4, Ka = 7.5 x 10-3
H2CO3, Ka = 4.6 x 10-7
NaH2PO4, Ka = 6.2 x 10-8
NaHCO3, Ka = 4.4 x 10-11
Ka = 4.8 x 10-13
6. Phosphoric acid is a weak acid and can be used to prepare buffer solutions. If 1L of 0.01M phosphoric acid has a starting pH of 7.4, and then an amount of 0.1M HCl is added to this buffer to change the pH to 5.6, what volume of 0.1M HCl has been added?
about all this chemistry review? This
one will calm your nerves:
Acetylcholine is a potent neurotransmitter.
Concentrations in the synapses between nerves is regulated by the enzyme
acetylcholinesterase. This enzyme
degrades acetylcholine to choline and acetic acid.
The acetic acid then dissociates to acetate ion and hydrogen ion.
How do we know that it completely dissociates? (Hint: the pH of the
synapse is between 6.6 and 7.5)