11. Redox Rxns

Question 1

[O] #’s for elemental states vs mono atomic ions

Answer 1

0 vs their charge

Question 2

How to find oxidation state?

Answer 2

of nml e- in elemental form - # of bonded e-

Question 3

What’s a disproportionation/dismutation rxn? What’s an example?

Answer 3

when something gets reduced and oxidized simul in same rxn; ex: hydrogen peroxide

Question 4

How to balance redox rxns in acid?

Answer 4

1) Write out half rxns (figure out which is is red and which one is ox)
2) balance non-O/H atoms
3) balance O by adding H2O, balance H by adding H+
4) balance charges by adding e-
5) make # of e- equal for each half rxn (common factor/coeff type thing)
6) put together reactants on one side, put together products on other side, simplify to make one big rxn

Question 5

How to balance redox rxns in base?

Answer 5

1) Write out half rxns (figure out which is is red and which one is ox)
2) balance non-O/H atoms
3) balance O by adding H2O, balance H by adding H+
4) balance charges by adding e-
5) make # of e- equal for each half rxn (common factor/coeff type thing)
6) add OH- to each side to balance out H+
7) put together reactants on one side, put together products on other side, simplify to make one big rxn

Question 6

Exceptions for finding oxidation state?

Answer 6

Usual unless paired with more electronegative elements (ex: HCl has +1 H and -1 Cl, but HOCl has +1 H, +1 Cl, and -2 O); usual unless paired with less electronegative elements (ex: HCl has +1 H and -1 Cl, but NaH has +1 Na and -1 H)

Question 7

How to find formal charge? How to find valence e-?

Answer 7

# ve- in free atom minus # of ve- in bonded atom
Group # on periodic table

Question 8

Half rxn method/ion e- method

Answer 8

When redox rxns are balanced by splitting into ox rxns and reduction rxns

Question 9

Potentiometeric titration

Answer 9

Form of redox titration in which an indicator is isn’t used —> use voltage instead