4.2 - Electrolysis Flashcards
Why do metals above carbon in the reactivity series have to be extracted using electrolysis?
They are too reactive and cannot be reduced by carbon
Why is electrolysis expensive?
Large amounts of energy are required to melt the ores and produce the electrical current
What are the first 6 metals in the reactivity series? (In order)
Potassium, sodium, lithium, calcium, magnesium, aluminium
How do you extract the metals above carbon in the reactivity series?
Extracted by electrolysis of molten chloride or molten dioxide
What are the 4 elements that come after carbon in the reactivity series?
Zinc, iron, hydrogen, copper
How do you extract the elements below carbon in the reactivity series?
Extracted by heating with a reducing agent such as carbon or carbon monoxide in a blast furnace
What 2 metals in the reactivity series are found as a pure element?
Silver and gold
In the electrolysis of aqueous solutions, the water molecules dissociate to form what two ions?
H+ and OH-
In the electrolysis of aqueous solutions, what ions are attracted to the positive electrode (anode)?
OH- ions and non metal ions
In the electrolysis of aqueous solutions, if both halide ions and OH- are present, what is being discharged at the anode?
The halide ion will be discharged, losing electrons an forming a halogen.
In the electrolysis of aqueous solutions, if no halide ions are present what is discharged at the anode and what does it lose electrons to form?
OH- is discharged and it loses electrons to form oxygen
In the electrolysis of aqueous solutions, what is attracted to the negative electrode (cathode)?
H+ and metal ions
In the electrolysis of aqueous solutions, if the metal is above hydrogen in the reactivity series what will be produced and what can you observe at the cathode?
Hydrogen will be produced and bubbling will be seen at the cathode.
