Chemistry HT3
what is electrolysis
The process that splits ionic compounds into their different elements using a solution that conducts electricity.
what are electrolytes
An ionic compound that produces a solution that conducts electricity when dissolved in water.
what is a anode.
Positive electrode.
what is a cathode
Negative electrode.
How many electrodes are there in electrolysis?
2
what is a an anion
Negatively charged ion.
what is a cathode
Positively charged ion.
What is a disadvantage of using electrolysis to extract reactive metals?
high cost of equipment and energy
In the electrolysis of aqueous solutions, what products can form at the anode?
Oxygen gas
A halogen
what are some examples of halogens
Halogens are a family of chemical elements that includes fluorine (F), chlorine (Cl), bromine (Br), and iodine (I)
The products of the electrolysis of aqueous solutions are slightly tricky to predict. Why?
the water molecules in the solution split up to give hydrogen (H+) and hydroxide (OH-) ions.
Which reactions happen at which electrode?
Cathode
Reduction reactions i.e. positively charged ions gain electrons.
Anode
Oxidation reactions i.e. negatively charged ions lose electrons.
What region of the pH scale would a substance that forms H+ be on?
Red
What is the name given to a reaction that involves losing oxygen?
Reduction
when do you use reduction and electrolysis in terms of the reactivity series
Metals more reactive than carbon, such as aluminium, are extracted by electrolysis, while metals less reactive than carbon, such as iron, may be extracted by reduction with carbon.
what happens to metals below hydrogen on the reactivity table
they are mostly pure so they're left
The reactivity of a metal is linked to how easy it is for a metal to form its what
positive ion
Reactions of reactive metals with water
metal + water → metal hydroxide + hydrogen
what is the neutralisation equation
alkali + acid → salt + water
Which element is used for extracting metals from their compounds by reduction?
carbon
What are the products of reactions between metals and acids?
Hydrogen gas
A salt
What happens to a substance when it is reduced?
Loses oxygen
Gains electrons