1: In the following reaction, what is the formal oxidation number of Mn in its oxidized form?
60s
+2
+5
+6
+7
2: Estimate the equivalence point for the following titration:
90s
0.98 V
1.97 V
1.61 V
0.36 V
3: For a galvanic cell, reduction occurs at the ______ and oxidation occurs ______.
30s
cathode; anode
anode; cathode
salt bridge; cathode
idk honestly
4: Which equation relates pH and reduction potential?
30s
A
C
B
D
5: What is equation B (Nikolsky) used for?
40s
Calculating E at non-equilibrium concentrations
Relating pH and E.
Determination of E for an ion-selective electrode.
6: What properties should a practical reference electrode have?
20s
Nernstian response (59.2mV / 10-fold change in concentration per n)
Eref stable after changes in T or passing current through
No reaction with atmosphere or other side reactions
Can operate as cathode only
7: When performing a potentiometric titration, what is the relative error of the your calculate concentration if the uncertainty in your potential measurement is 1 mV?
20s
0.02
2
0.04
4
8: When looking at atomic or molecular emission spectra, what does the intensity of a peak depend on?
30s
the wavelength - shorter wavelength = more intense
number of atoms in initial state * probability of transition
number of atoms overall
probability of transition only
9: When performing an EDTA titration, how can you deal with a competing ligand?
30s
Use a masking agent, another ligand that can bind to you metal of interest.
Add NH3 to keep analyte soluble
Choose a pH that keeps ligand from interfering.
Use releasing agent, another cation that binds to the competing ligand stronger.