electrolysis

Question 1

why cant sold ionic compounds conduct electricity

Answer 1

the ions are locked and cant move

Question 2

how can ionic compounds conduct electricity and why

Answer 2

though being melted or dissolved in water
the forces of attraction are broken so ions are free to move and conduct elect

Question 3

what are ionic compounds that can conduct elec called

Answer 3

electrolytes

Question 4

what is the negative electrode

Answer 4

cathode

Question 5

what is the postive electrode

Answer 5

anode

Question 6

what is the cathode attracted to

Answer 6

protons

Question 7

what is anode attracted to

Answer 7

electrons

Question 8

what is high in aluminium oxide
Al2O3

Answer 8

its melting point approx 2000^c

Question 9

what is Al2O3 mixed with and why

Answer 9

with creolite to lower melting point
reducing energy and energy costs

Question 10

in Al2O3 what are the electrodes made of

Answer 10

graphite (carbon)

Question 11

in Al2O3 the ions are..

Answer 11

ions are free to move

Question 12

what is Al+3 attracted to and the type of reaction

Answer 12

cathode
reduction

Question 13

what is the half equation for Al+3

Answer 13

Al+3 + 3e- —> Al

Question 14

what is O2- attracted to and the type of reaction

Answer 14

anode
oxidation

Question 15

what is O2-‘s half equation

Answer 15

2o2-4e—>o2

Question 16

why does the anode have to be replaced regularly

Answer 16

the oxygen molecules react with the graphite to form co2 which damages it

Question 17

why is electrolysis of Al2O3 expensive

Answer 17

melting compounds require lots of energy and lots of energy required to produce electric current

Question 18

what happens with electrolysis of aqueous solutions and equation

Answer 18

water molecules ionise to form hydrogen ions and hydroxide ions
H2O —-(rvrs) H+ + OH-

Question 19

what ions are formed with CuSO4 (aq)

Answer 19

Cu2+/H+ and SO4.2-/OH-

Question 20

what happens when the metal element is more reactive than hydrogen in aq

Answer 20

then hydrogen will be produced at the cathode

Question 21

what happens when the metal element is less reactive than hydrogen in aq

Answer 21

then the said element is produced at the cathode

Question 22

for CuSO4 what is used as an inert electrode

Answer 22

platinum

Question 23

what is produced at the anode for CuSO4

Answer 23

4OH- —-> O2 + 2H2O + 4e-
ox

Question 24

for CuSO4 what is produced at cathode

Answer 24

Cu2+ + 2e- —> Cu
reduc

Question 25

what happens if the aq solution contains halide ions

Answer 25

halogen is produced at the anode