ELECTROLYSIS

Question 1

Why can’t colavent compounds conduct electricity

Answer 1

They have no free charged particles

Question 2

DEFINE: ELECTROLYSIS

Answer 2

A chemical change which occurs when an electrical current is passed through a compound which is either molten or in solution

Question 3

What materials are used for the electrodes

Answer 3

-CARBON as it’s fairly inert
(Sometimes PLATINUM)

Question 4

Water in aqueous solution electrolysis

Answer 4

Water molecules DISSOCIATE to from H+ ions and OH- ions

Question 5

What is produced at the ANODE in aqueous solutions

Answer 5

OH- ions and halide ions are attracted to the ANODE
-if there are halide ions, it’ll be discharged and lose electrons at the anode and form a halogen
-if there are no halide ions, the OH- ions will become discharged and lose electrons to form oxygen
-the other negative ion will always remain in the solution

Question 6

What is produced at the CATHODE in aqueous solutions

Answer 6

-CATIONS, H+ or a metal ions are attracted to the CATHODE
-if the metal ion is BELOW hydrogen in the reactivity scale, the metal ion will become discharged, gain electrons and form the metal
-if the metal ion is ABOVE hydrogen, the h+ ions will become discharged and gain electrons to form hydrogen gas
-this is because the most reactive ion will remain in the solution

Question 7

Why do we obtain less chlorine than expected in the electrolysis practical

Answer 7

CHLORINE is more SOLUBLE in water

Question 8

WHY is hydrogen produced at the CATHODE if the metal ions are more reactive?

Answer 8

The more reactive something is, the greater tendency it has to form an ion
Therefore, the more reactive something is, the harder it is to turn it back into an atom
The lower the position of an element in the reactivity scale, the more easily it will accept an electron
Therefore, it is easier to add an electron to a hydrogen ion to form a hydrogen atom