PORTAGE LEARNING CHEM 104 FINAL EXAM QUESTIONS AND ANSWERS Rules for determining oxidation number -----

PORTAGE LEARNING CHEM 104
FINAL EXAM QUESTIONS AND
ANSWERS


Rules for determining oxidation number ------------CORRECT ANSWERS--------1. H has oxidation
number of +1 paired with nonmetals and -1 with metals

2. Oxygen has a number of -2

3. Metals have a charge equal to their group number

4. Halogens are usually -1

5. The sum of oxidation numbers for all atoms in a molecule is the ions charge



Oxidation number for HBr ------------CORRECT ANSWERS--------H: +1

Br: -1



Oxidation numbers for HNO3 ------------CORRECT ANSWERS--------H: +1

N: +5

O: -2



Redox Reaction Definition ------------CORRECT ANSWERS--------Type of reaction involving the transfer
of electrons between two species



Define oxidation ------------CORRECT ANSWERS--------loss of electrons



Define reduction ------------CORRECT ANSWERS--------gain of electrons



Ag + Au^+1 = Ag^+1 +Au ------------CORRECT ANSWERS--------Ag: oxidized (lost electron)

Au: reduced (gained electron)

, Write half reactions for:

Ag + Au^+1 = Ag^+1 +Au ------------CORRECT ANSWERS--------Ag = Ag^+1 + 1e-

Au^+1 + 1e- = Au



electrochemical cell ------------CORRECT ANSWERS--------Device that contains the reactants and
products of a redox system, but prevents physical contact between the reactants the transfer of
electrons is indirect and requires an external circuit



Galvanic cell ------------CORRECT ANSWERS--------An electrochemical cell in which a spontaneous
redox reaction takes place



Half cell ------------CORRECT ANSWERS--------Contains the redox conjugate pair of a single reactant
(there's two per galvanic cell)



Anode ------------CORRECT ANSWERS--------The cell that contains the oxidation reaction



Cathode ------------CORRECT ANSWERS--------The cell that contains the reduction reaction



Salt bridge ------------CORRECT ANSWERS--------A tube filled with inert electrolyte solution that
connects the anode and the cathode



Inert electrode ------------CORRECT ANSWERS--------Provides or accepts electrons in the redox
reaction



Active electrode ------------CORRECT ANSWERS--------Constructed from a member of the redox
reaction



Write cell schematic for:

Ag + Au^+1 = Ag^+1 +Au ------------CORRECT ANSWERS--------1. Start with the anode side, which is the
oxidation reaction and then after that do the cathode side, which is a redox reaction.



Ag | Ag^+1 || Au^+1 | Au