C6 Electrolysis Flashcards
(34 cards)
What happens when an electric current is passed through a molten ionic compound ?
The compound decomposes or breaks down
Liquid and solutions that are able to conduct electricity are called ?
Electrolytes
Can covalent compounds conduct electricity ?
No
What is an electrode ?
A rod of metal or graphite through which an electric current flow into or out of an electrolyte
What is an electrolyte ?
Ionic compound in molten or dissolved solution that conducts electricity
What is an anode ?
The positive electrode of an electrolysis cell
What is an anion ?
A negatively charged ion which is extracted to the anode
What is a cathode ?
The negative electrode of an electrolysis cell
What is a cation ?
Positively charged ion which is extracted to the cathode
When ionic compounds are in a solid state, can they conduct electricity ?
No they cannot
How are ions able to move ?
They can only do so in the molten state or when dissolved in a solution
What does electrolysis mean ?
Breaking down using electricity
How do you set up an electrical circuit for electrolysis ?
You have two electrodes that dip into the electrolyte with a gap between them . The electrodes are conducting rods . One of these is connected to the positive terminal of a power supply . This positive electrode is called the anode . The other electrode is connected to the negative terminal and is called the cathode
What are electrodes often made of ?
An unreactive substance such as graphite or sometimes expensive platinum metal
What happens during electrolysis ?
During electrolysis , positively charged ions move to the cathode ( negative electrode ) . At the same time , the negative ions move to the anode ( positive electrode ) as opposites attract
What happens when ions reach the electrodes ?
They lose their charge and become elements
What is an example of electrolysis ?
Zinc chloride - zinc + chlorine . Zinc chloride is an ionic compound , they do not conduct electricity when they are solid , once melted they are free to move around toward the electrodes . The positive zinc ions , move towards the cathode ( negative electrode ) . At the same time , the negatively charged chloride ions move towards the anode ( positive electrode )
Negatively charged ions lose electrons to become …
Neutral atoms
Positively charged ions gain electrons to become …
Neutral atoms
Gaining electrons is called …
Reduction
Losing electrons is called ….
Oxidation
When electrolysis happens in an aqueous solution , the less reactive element , either hydrogen or the metal is usually produced at the cathode . What could you get at the anode ?
. Oxygen gas given off , from discharged hydroxide ions produced from water
. A halogen produced if the electrolyte is a solution of a halide
Aluminium is a very important metal . The uses of the metal its alloys include :
. Pans
. Overhead power cables
. Aeroplanes
. Cooking foil
. Drink cans
. Window and patio door frames
. Bicycle frames and car bodies
Aluminium is quite a reactive metal . What must you use to displace aluminium from its compounds ?
Electrolysis
