Electrolysis Flashcards
Describe how copper metal forms at negative electrode
Copper (II)ions are +charged attracted to cathode which is negatively charged
And gained electrons
Appearence of copper forms on negative electrode
Pink brown solid
Why molten sodium chloride conducts electricity
As it has free moving ions on molten
Why sodium metal doesn’t form in electrolysis of an aqueous solution of sodium chloride
as sodium more reactive than hydrogen
Why using sodium chloride that is not completely dry could cause these small explosions
Water react with sodium produce hydrogen which burn in air cause small explosion
Why copper conducts electricity
As it has free decolaised moving electrons
Explain why electrolysis doesn’t occur unless lead(ii) bromide is molten
As there is free moving ions when molten as ions are fixed position in lattice so can’t move on solid
Explain why the lamp doesn’t light when lead(II) bromide is solid
As doesn’t conduct electricity, as all ions are in fixed position in lattice
What is meant by electrolysis
Decomposition of electryote by electricity
Why electrons are no longer flowing through the wires
As no gaining electrons at electrodes
Why student does not use zinc electrode in her expirment
Because it’s not inert as zinc will react with electrode
Suggest why copper (Ii)sulphate solution contain some oH- ions
OH- ions comes from water
Predict what will happen to conductivity of mixture when lead(ii)nitrate is in excess
Conductivity increase
What is meant by redox reaction
Oxidation and reduction produce in same time
Why volume of hydrogen collected should be twice volume of oxygen
As moles of hydrogen double oxygen
