Chapter C6- Electrolysis Flashcards
What two things make up ionic compounds?
Why don’t solid ionic compounds conduct electricity?
What happens when the compound is dissolved?
What are the non-metal ions always?
What do they attract to?
What are the metal ions always?
What do they attract to?
What is electrolysis?
Positive ions and negative ions.
Because the space between the particles has no charge so no current can pass through.
The space created (and the charge) creates a pathway for the electrons to flow through.
Negative.
The positive electrode.
Positive.
The negative electrode.
The splitting up using electricity.
What is the negative electrode called in electrolysis?
What is the positive electrode called in electrolysis?
What are the cations and so what do they attract to?
What are the anions and so what do they attract to?
What is the test for chlorine?
What is ionisation?
What is electrolysis?
What does this mean?
What are electrons written as when lost/added and why?
Cathode.
Anode.
Cations are positive and attract to the cathode (-).
Anions are negative and attract to anode (+).
When damp blue litmus paper goes white (CL2).
The loss or gain of electrons to form ions.
The loss or gain or electrons to form atoms again.
Electrolysis is the opposite of ionisation.
e-, because the electrons have a negative charge.
What do ions need to do once they are at the electrode and why?
What do metals always gain?
What do non-metals always lose?
Where do cations (+) attract to?
Where do anions (-) attract to?
What is electrolysis the formation of?
What do substances with - mean?
What do substances with + mean?
They need to gain electrons (+ ions) or lose electrons (- ions) to become atoms once again.
Metals always gain electrons.
Non-metals always lose electrons.
The cathode (-).
The anode (+).
The formation of ions to atoms
They’ve gained electrons
They’ve lost electrons.
What do half equations show?
What happens if water is present in a solution being electrolysed?
What do all gases travel around in?
Which group of gases don’t travel around like this?
What happens (usually) if you have a choice of two elements being produced at the electrode?
What happens to the least reactive one?
Where is the hydroxide ion often attracted to?
When does this not occur?
How can we extract aluminium?
Why can’t carbon be used to extract aluminium?
The ions going back to atoms at each electrode.
It complicates things as it too contains ions.
All gases travel around in pairs.
The noble gases.
The more reactive one will stay in the solution.
The least reactive one will turn back into atoms and come out of the solution.
To the anode.
Unless a halide ion is present (such as sodium chloride).
Using electrolysis.
Carbon can’t be used because it’s not reactive enough as it can’t displace aluminium from its compounds.
What is contained in bauxite?
What is this dissolved in before electrolysis and why?
What other use does this compound have?
Where are the aluminium ions attracted to and why?
Where are the oxide ions attracted to and why?
What happens to the aluminium?
What does the oxygen react with?
Why do these have to be replaced?
What are hydroxides?
What are oxides?
Aluminium oxide.
Molten cryonite because it has to be molten so that the ions can flow.
Molten cryolite is used to lower the melting point of aluminium oxide.
Aluminium ions are attracted to the negative electrode (because aluminium is positive).
Oxide ions are negative so are attracted to the positive electrode.
It’s then tapped off at the bottom of the electrolysis cell.
The hot carbon anodes making carbon dioxide gas.
The carbon anodes gradually burn away and need to be replaced regularly.
Alkalis.
Bases.
What are some of the uses of chlorine?
What are some of the uses of hydrogen?
What are some of the uses of sodium hydroxide?
What is something called if it’s oxidised?
What is something called if it’s reduced?
What happens to the positive ions?
What happens to negative ions?
What are the three products of the electrolysis of brine?
What are the black and red rods in a electrolysis practical (in terms of charge)?
- used to kill bacteria in swimming pools
- used in bleach (to make it).
Used in the making of margarine.
- used in bleach (and to make paper).
- used to make soap.
The reducing agent.
The oxidising agent.
They always reduce at the cathode.
They always oxidise at the anode.
Chlorine, hydrogen and sodium hydroxide (NaOH).
The red rods are positive and the black rods are negative.
