Electrolysis

Question 1

what are anions, cations, anodes and cathodes? (4 points)

Answer 1

anions: negatively charged ions
cations: positively charged ions
cathode: attracts cathodes (-ve electrode)
anode: attracts anodes (+ve electrodes) [gives out electrons)

Question 2

what is electrolysis? (1 point)

Answer 2

it is process of using electricity to break down or decompose a compound

Question 3

3 main points on electrolysis?

Answer 3

contains a pair of electrodes connected to the battery, usually dipped in an electrolyte.
electrical energy –> chemical energy
non-spontaneous reaction

Question 4

why cant solid electrolytes be used? (2 point)

Answer 4

In the solid state, ions are held in the lattice structure. Thus, they cannot conduct electricity as there are no mobile ions or electrons. (non electrolytes: sulfur, sugar, distilled water, organic compounds, e.g. ethanol)

Question 5

what happens at the cathode and anode respectively (2 points; hint: oxidation)

Answer 5

at the anode, oxidation takes place. at the cathode, reduction takes place. (Oh A Red Cat)

Question 6

differences between molten electrolytes and aqueous electrolyte. (2 points)

Answer 6

molten electrolytes are pure liquid that only have cations and anions in the liquid.
aqueous electrolytes contains water, made out of cations, anions, H+ and OH-

Question 7

what is the preferential discharge of anions?

Answer 7

sulfur, nitrate, Cl, Br, I, OH- (OH- lose electrons most readily, usually the one getting discharged)

Question 8

what is the preferential discharge of cations?

Answer 8

reactivity series (Au most likely to get discharged)

Question 9

what is the difference between active electrodes and inert electrodes?

Answer 9

active electrodes (active electrodes are usually copper, iron) take part in the reactions while inert electrodes do not (inert electrodes are usually platinum, carbon, graphite)