Chapter 2: Buffers Flashcards
PH scale equation
pH + pOH = 14
Ka represents
the level of dissociation of the acid
When strong acids are placed in water they
completely dissociate (Ka > 1)
When weak acids are placed in water they
partially dissociate (Ka<1)
Formula for pKa
pKa= -log(Ka)
When to use the Henderson- Hasselbalch equation
When HA and A- are both present in the solution
Midpoint of a titration curve is where
[HA]= [A-]
Buffer definition
Solution whose pH changes very little when small amounts of acid or base are added to it
Phosphate and bicarbonate buffer systems are essential in :
maintaining a cellular pH constant
How do buffers work?
they soak up excess H+ or OH ions when added to a solution
Buffering capacity increases with
increasing concentration of buffering agent
The pH range of a buffer is
+/- 1 from the pKa
Polyprotic acids are
molecules that have multiple groups that can be deprotonated
The titration curve of a polyprotic acid has how many curves?
The same number of groups that can be deprotonated, each connected together and increasing in PH each time
The pKa of 2 closesly associated acid-base groups are:
not independent
