C5) Electricity and Chemistry

Question 1

define electrolysis

Answer 1

the breakdown of an ionic compound when molten or in aqueous solution by the passage of electricity

Question 2

describe inert electrode

Answer 2

does not react with the electrolyte or products formed during electrolysis

Question 3

describe electrolyte

Answer 3

ionic compounds that are in molten state or dissolved in water

Question 4

describe anode and cathode (PANIC)

Answer 4

anode = positive cathode = negative

Question 5

what happens to anions in electrolysis?

Answer 5

(negative ions) they are attracted to the anode where they give up electrons (oxidised)

Question 6

what happens to cations in electrolysis?

Answer 6

(positive anions) they are attracted to the cathode where they gain electrons (reduced)

Question 7

rule for what forms at the anode

Answer 7

Hydrogen is produced unless the cations in the ionic compound from the metal are less reactive than hydrogen

Question 8

rule for what forms at cathode

Answer 8

Oxygen is produced UNLESS the ionic compound contains halide ions (I-,Cl-, Br-)

Question 9

what are the uses of electroplating?

Answer 9

coating a cheaper metal with a more expensive one (eg. silver coating on cutlery)