Experimental Investigations ❮ 305(b)(^7) Equivalence point at pH < 7.
pH > 1
Volume added
pH
You get 1 point for this graph. You get an additional point for noting that the
equivalence point is greater than 7.
(c)
Volume added
pH
You get 2 points for this graph if you show both steps. You get 1 point for showing
only one step.
(d) There are several related ways to do this problem. One method is to split the sample
into two portions. Titrate one portion to the equivalence point. Add the titrated sample
to the untitrated sample, and add a volume of deionized water equal to the volume of
NaOH solution added. The pH of this mixture is equal to the pKa of the acid (this
corresponds to a half-titrated sample).
You get 1 point for anything concerning a half-titrated sample and an additional
1 point for pH = pKa.
(e) The pH at the equivalence point must be close to the pKa of the indicator.
You get 1 point for this answer.
Total your points. There are 10 points possible.
❯ Rapid Review
Reviewing the experiments should include looking at the synopsis, apparatus, calculations,
and comments, as well as the appropriate concept chapters, if needed.
-^ Pay particular attention to any experiment you did not perform.
-^ Be familiar with the equipment used in each experiment.
-^ Know the basic measurements required in each experiment.
-^ Know what values are measured and which are calculated.
-^ Pay attention to significant figures.
-^ Balances are used to measure the mass of a substance, not the moles.