Electrolysis Flashcards
What are electrolytes
They are ionic compounds that dissolve in water to create a solution that conducts electricity
What are the two electrodes involved in electrolysis
Cathode - positive ions move here
Anode - negative ions in an electrolyte move here
What is the function of electrolysis
To split up ionic compounds into their elements
What is produces at the anode
If halide ions are present the respective halogen forms
If no halide ions are resent, oxygen is formed
What happens at the cathode
If the metal is more reactive than hydrogen, hydrogen is produced
If the metal
Is less reactive than hydrogen, the metal is produced
Why do products from electrolysis of NaCl need to be separated
Mixture of H and Cl in air can induce an explosion
Why is the bayer process important
Used to obtain alumina from bauxit
Why is the hall heroult process important
Used to obtain pure Aluminium from alumina
Properties of diaphragm cell
Porous diaphragm so products of electrolysis will be NaOH contaminated with NaCl (sold as bleach)
Cheap
Properties of membrane cell
Expensive
Cell only permeable to ions with a positive charge so NaOH will not be contaminated
Half equations for products at anode and cathode for electrolysis of brine
Cathode - 2H20 + 2e > H2 + 2OH
Anode- 2Cl- > Cl2 + 2e-
what happens when an ionic compound is melted
when an ionic compound is melted, the ions within the compound become free to move therefore allowing them to undergo electrolysis
