Chapters 20 and 21

Question 1

Oxidized

Answer 1

loses electrons (reducing agent)

Question 2

Reduced

Answer 2

gains electrons (oxidizing agent)

Question 3

Anode (electrolytic)

Answer 3

oxidation, positive electrode

Question 4

Cathode (electrolytic)

Answer 4

reduction, negative electrode

Question 5

Where ions move through in voltaic cells

Answer 5

move through the salt bridge, negative ions move to positive electrode and positive ions move to negative electrodes

Question 6

Where electrons move through in voltaic cells

Answer 6

move through the wire

Question 7

Voltaic cell description

Answer 7

spontaneous oxidation-reduction reaction

Question 8

Voltaic cells

Answer 8

produce energy

Question 9

Electrolytic cells

Answer 9

absorb energy

Question 10

Electrolysis

Answer 10

process of electrolytic cell

Question 11

Rules for assigning oxidation numbers

Answer 11

oxidation number of monatomic ions are equal to ionic charge
hydrogen in a compound is +1, except in metal hydrides it’s -1
oxygen in a compound is -2
oxidation numbers of uncombined atoms are 0
neutral compounds’ oxidation number’s sum must equal 0
the sum of oxidation numbers in a polyatomic ion must equal the ionic charge of the ion

Question 12

Steps for balancing a redox reaction

Answer 12

assign oxidation numbers
identify which atoms were oxidized/reduced
connect atoms that undergo oxidation and undergo reduction with bracket lines
make total increase in oxidation number equal to the total decrease in oxidation number by using appropriate coefficients

Question 13

Difference between dry voltaic cells and wet voltaic cells

Answer 13

wet cells have a liquid electrolyte while dry cells have a paste electrolyte

Question 14

Main difference between voltaic and electrolytic

Answer 14

electrolytic - electrons are pushed by outside source

voltaic - electrons move because of spontaneous redox reaction

Question 15

Anode (voltaic)

Answer 15

negative, oxidizing

Question 16

Cathode (voltaic)

Answer 16

positive, reducing

Question 17

Oxidizing

Answer 17

gains electrons

Question 18

Reducing

Answer 18

loses electrons

Question 19

Product of electrolysis of water

Answer 19

hydrogen and oxygen gases

Question 20

Electroplating

Answer 20

deposition of a thin layer of metal on an object in an electrolytic cell (one metal dissolves and it goes onto the other, like the aluminum and copper)