Electrolysis

Question 1

What does electrolysis loosely translate to

Answer 1

splitting up with electricity

Question 2

what is done in the process of electrolysis

Answer 2

• electric current is passed through an electrolyte
• ions move towards the electrodes where they react
• reaction causes compound to decompose

Question 3

what is an electrolyte with examples

Answer 3

• a molten or dissolved ionic compound that can conduct electricity (what you are electrolysing)
• the metal and the non-metal (aluminium oxide)

Question 4

what happens to the positive ions in electrolysis

Answer 4

positive ions in the electrolyte move towards the cathode and gain electrons (reduced)

Question 5

what happens to the negative ions in electrolysis

Answer 5

negative ions in the electrolyte move towards the anode and lose electrons (oxidised)

Question 6

what is a cathode

Answer 6

a negative electrode

Question 7

what is an anode

Answer 7

a positive electrode

Question 8

what does the movement of ions in the electrolyte to electrodes result in

Answer 8

the creation of a flow of charge through the electrode

Question 9

what does the loss or gain of electrons of the ions form and what happens to it

Answer 9

the uncharged element which is discharged from the electrolyte

Question 10

what is an electrode

Answer 10

a solid that conducts electricity and is submerged in the electrolyte

Question 11

why cant an ionic solid be electrolysed but molten ionic compounds can

Answer 11

• ionic solids cant be electrolysed because the ions are in a fixed position so they arent free to move
• molten ionic compounds can because the ions can move freely and conduct electricity

Question 12

what happens to positive metal ions in electrolysis, with a symbol equation as an example

Answer 12

• they are reduced to the element at the cathode

- Pb2+ + 2e- = Pb

Question 13

what happens to negative non-metal ions in electrolysis, with a symbol equation as an example

Answer 13

• they are oxidised to the element at the anode

- 2Br- = Br2 + 2e- (2e- is the loss of the electrons)

Question 14

if you want to extract a metal but its too reactive to be reduced with carbon, what method would be used

Answer 14

electrolysis

Question 15

what are the ecological issues with electrolysis

Answer 15

• very expensive method of extraction

- lots of energy is needed to melt the ore and produce the required current

Question 16

what is the most important mnemonic to remember when it comes to electrolysis

Answer 16

- OILRIG
Oxidisation
Is (the)
Loss of electrons
Reduction
Is (the)
Gain of electrons

Question 17

in a setup for electrolysis, which side are the cathodes and anodes on and in what direction are the electrons flowing

Answer 17

• cathode is on the left
• anode is on the right
• electrons flow into the cathode (the the left)

Question 18

how would you prepare a molten iomci substance to be electrolysed

Answer 18

• put solid ionic substance in a crucible
• the ionic substance will become the electrolyte
• heat the crucible wjth a bunsen burner until the solid is molten
• once solid is molten dip two clean inert electrodes into electrolyte
• connect electrodes to power supply using wires and clips

Question 19

why should you heat the solid ionic substance with a bunsen burner in a fume cupboard

Answer 19

to avoid releasing any toxic fumes into the room

Question 20

what are examples of inert electrodes and why are they inert

Answer 20

• graphite or platinum

- they are inert because they are unreactive

Question 21

how can you check to make sure a current is flowing through the electrodes

Answer 21

put an ammeter or a bulb in series with your circuit to check you have set it up correctly