Electrolysis Paper 1 Flashcards
What is the method for electrolysis of molten compounds?
Beaker containing electrolyte has electrodes placed in.
-At the right positive electrode anode and left negative electrode cathode.
-Join electrodes with wire so electrons can flow and use battery or power supply to drive this
-Negative non metal ions attracted to anode and discharged
-Positive metal ions attracted to cathode and discharged
-Oxidised at anode
-Reduced at cathode
What is electrolysis?
Breakdown of an ionic compound by using electricity
What are electrodes?
Solid conductors made up of metal or carbon.
What is an electrolyte?
Liquid or solution that contains ionic compound(ions are free to move).
What should happen if electrolytes are soluble or insolube?
-If soluble will dissolve in water to become electrolyte
-If not soluble like lead bromide melt into molten liquid so ions are free to move
How are metal oxides usually seperated?
-Reduction with carbon and carbon displaces
What are cons of electrolysis?
Required with more reactive metals but is very expensive and requires lots of energy.
How do you extract aluminium from aluminium oxide?
-Purify Bauxite then mix with cryolite to lower melting point.
-Melt into molten aluminium oxide
-Do normal electrolysis process
What happens when an aqueous solution is prepared for electrolysis?
- Water breaks down to producer Hydrogen and Hydroxide ions.
What happens at cathode during electrolysis of aqueous solution?
-Cathode will attract positive metal and hydrogen but only discharge on of them
-Least reactive gets discharged(hydrogen lies between copper and iron).
What happens at the anode during electrolysis of aqueous solutions?
-At anode negative non metals and hydroxide
-If a halide is present (F, Cl , Br , I , At) then gets discharged if not hydroxide gets discharged.
