Chemical Changes Flashcards
What is oxidation?
When a substance gains oxygen and loses electrons
What is reduction?
When a substance loses oxygen and gains electrons
What is the reactivity of metals?
The series shows the metals in order of their reactivity
What is a displacement reaction?
A reaction where a more reactive metal displaces a less reactive metal from a compound
How are unreactive metals found in Earth?
In their natural state
How can metals less reactive than carbon be extracted?
Reduction with carbon. Carbon displaces the metal in a metal oxide - gets oxidised to carbon oxides. Metal from the metal oxide gets reduced to the pure metal
How are metals more reactive than carbon extracted?
By electrolysis
What is the general equation for a reaction between metals and acids? What type of reaction is this?
Metal + acid —> salt + hydrogen
Redox reaction, also a displacement reaction
Which metals in the reactivity series will react with acid?
Those above hydrogen
What is the general equation for a neutralisation reaction?
Base + acid —> salt + water
What is the general equation for the reaction between metal carbonate and acid?
Metal carbonate + acid —> salt + water + carbon dioxide
What is the general equation for the reaction between metal oxides and acids?
Metal oxide + acid —> salt + water
What is a redox reaction?
A reaction where both oxidation and reduction occurs
Explain in terms of gain or loss of electrons which species has been oxidised and which species has been reduced when magnesium reacts with hydrochloric acid
-Magnesium has lost electrons and thus has been oxidised (Mg to Mg2+)
-The hydrogen in HCl has gained electrons and thus has been reduced (H+ to H2)
How is a soluble salt formed?
- React the excess acid with some insoluble chemical
- Filter off the leftovers
- Crystallise the product