C4 Chemical Changes FT Flashcards
What is produced when a metal reacts with oxygen?
Metal oxide
What is the name given to the type of reaction when there is addition of oxygen (the metal loses electrons).
Oxidation
What is the reactivity series?
Order of elements from the most to least reactive.
If a metal is reacted with a compound with a less reactive metal in it what will happen?
The more reactive metal will displace the less reactive metal from the compound
Why are some metals more reactive than others?
They form positive ions more easily
What is produced when a metal reacts with an acid?
A salt
What is a base?
A metal oxide or metal hydroxide
What is produced when a metal reacts with an acid?
A salt + hydrogen
When is produced when an acid reacts with a base?
A salt + water
What is an alkali?
A base which dissolves in water (is soluble)
What salt would be made in the reaction between sodium hydroxide and hydrochloric acid?
Sodium chloride
What type of salt is made if sulphuric acid is used?
A sulphate
What type of salt is made if nitric acid is used?
A nitrate
What type of salt is made if hydrochloric acid is used?
A chloride
What is made when an acid reacts with a carbonate?
A salt + water + carbon dioxide
What is the pH of a strong acid?
1
What is the pH of a neutral solution?
7
What ions do acids produce?
H+
What ions do alkalis produce?
OH-
Why do ionic compounds have to be dissolved in water or molten for electrolysis?
So that the ions can move
What is the positive electrode called?
Anode
What is the negative electrode called?
Cathode
Why is cryolite added to aluminium oxide to extract aluminium by electrolysis?
To lower the melting point and reduce so reduce energy needed
Why is the anode constantly replaced in the electrolysis of aluminium oxide?
The oxygen reacts with the carbon of the electrode to make carbon dioxide.
What 2 ions do water molecules break down into in the electrolysis of aqueous solutions?
Hydrogen and hydroxide
What moves to the cathode of electrolysis of aqueous solutions?
The least reactive positive ion.
What moves to the anode of electrolsis of aqueous solutions?
If a halide (Gp 7) is present it will go to the anode, if not oxygen will go.
