REDOX

Question 1

Redox Reactions

Answer 1

caused by competition of atoms for electrons

Question 2

Oxidation

Answer 2

the LOSS of electrons, charge becomes more positive

Question 3

Reduction

Answer 3

the GAIN of electrons, charge becomes more negative

Question 4

Oxidation number

Answer 4

the “apparent change” on an atom in a compound, due to difference in electronegativity and bonding

Question 5

Ion

Answer 5

charge an atom becomes when it gains or loses electrons

Question 6

Redox Rule #1

Answer 6

• neutral compounds must sum to the total charge of zero (NaCl, AlPO4)

Question 7

Redox Rule #2

Answer 7

• polyatomic ions have a sum total = to the ion’s charge (PO4 ^ -3 = total charge = -3)

Question 8

Redox Rule #3

Answer 8

any atom uncombined has a oxidation of zero, because atoms are neutral

Question 9

Redox Rule #4

Answer 9

a monoatomic ion has a oxidation that equals its ion charge

Question 10

Electronegativity

Answer 10

the attraction for another atom’s electrons

Question 11

Redox Rule #5

Answer 11

in binary compounds the more electronegative element is assigned FIRST (more active non-metal)

Question 11

Redox Rule #6

Answer 11

all elements in group 1 and 2 have the oxidation states +1 and +2 and aluminums oxidation state is +3

Question 11

Redox Rule #7

Answer 11

fluorine will always have a -1 oxidation number

Question 12

Redox Rule #8

Answer 12

because fluorine is always -1, oxygen can be +
2, in peroixde oxygen is -1

Question 13

Redox Rule #9

Answer 13

hydrogen almost always will be +1 but if it combines with a metal to make a hydride it will be -1

Question 14

Redox

Answer 14

an overall reaction that is defined by the transfer of electrons and can be broken down into 2 reactions that both occur simultaneously

Question 15

Oxidizing Agent

Answer 15

the substance that makes something else undergo oxidation

Question 16

Reducing Agent

Answer 16

any substance that makes something else gain electrons

Question 17

Half Reaction

Answer 17

an equation which shows only a reduction or oxidation (shows conservation of mass, charge, and energy)

Question 18

Voltaic Cells

Answer 18

are electrochemical cells which involve a spontaneous redox reaction where chemical energy is converted into electrical energy

Question 19

Anode

Answer 19

in a voltaic cell the anode is - and is the site of oxidation

Question 20

Cathode

Answer 20

in a voltaic cell the cathode is + and is the site of reduction

Question 21

flow of electrons in a voltaic cell

Answer 21

electrons move from anode to cathode through the wire

Question 22

Anode and Cathode - mass size

Answer 22

• anode decreases in mass/size
• cathode increases in mass/size

Question 23

What is happening with the salt bridge?

Answer 23

ions both negative and positive are moving through the salt bridge in the direction of the electrode with same charge to maintain neutrality, then the battery will die and voltage will read zero to come to a state of equilibrium

Question 24

Maximum Battery Voltage or Cell Potential formula

Answer 24

cell potential (V) = reduction potential (v) - oxidation potential (v)

Question 25

Electrolytic cells

Answer 25

electrolysis is a non-spontaneous reaction that requires electricity; process by which we use elec t break down a compound into its component molecule

Question 26

Allotrope

Answer 26

one or more form of a chemical element that can exist in the same physical state

Question 27

Mass Number

Answer 27

total number of protons and neutrons in an atom

Question 28

Heat of Vaporization

Answer 28

the amount of heat needed to turn 1 g of a liquid into a vapor