Chemical Changes

1) What is a Reaction ?

Reactions - metals with oxygen - process called oxidation - forms metal oxides
potassium + oxygen
sodium + oxygen

Reactions - metals with water - form metal hydroxide and hydrogen gas
potassium + water

Reactions - metals with acids - produce salt and hydrogen gas
magnesium + hydrochloric acid
zinc + sulfuric acide
iron + sulfuric acid

2) Can you name the four factors that affect the rate of reaction ?
Temperature
Surface Area
Concentration / Pressure
Any Catalysts

3) What is an Enzyme ?
This is a biological catalyst

4) Can you give some examples of chemical reactions ?
Sodium + Hydrogen = Sodium Hydride
Hydrogen + Oxygen = Water
Sodium + Hydrochloric Acid = Sodium Chloride + Hydrogen
Hydrogen + Carbon = Methane Gas

5) What is Neutralisation ?
When an acid and a base are mixed together, they react
If an acid is reacted with a base then salt and water is created and its PH will be 7.
This process is called neutralisation.
eg - acid + metal oxide = salt + water
eg - acid + metal hydroxide = salt + water
eg - acid + metal carbonate = salt + water + carbon dioxide

6) What is the Haber Process ?
It produces Ammonia from Nitrogen and Hydrogen

7) How can you measure the PH of a solution ?

8) What is the Reactivity Series ?
A list of metals in order of reactivity.
Potassium
Sodium
Lithium
Calcium
Magnesium
Aluminimum
Carbon (GAS)
Zinc
Iron
Tin
Lead
Hydrogen (GAS)
Copper
Silver
Gold
Platinum

9) In the Reactivity Series which metals react with Acid
metals above hydrogen

10) Why do metals conduct electricity ?
Delocalised electrons can mpve freely and carry charge

11) What is a Displacement Reaction ?
When a metal or carbon comes into contact with a metal that is in a compound they may be a reaction.
When the metal in the compound is lower in the reactivity series the metal in the compound will be displaced.
A more reactive metal displaces a less reactive metal.

12) Can you give an example of a displacement reaction ?
Iron + Copper Sulfate = Iron Sulfate + Copper
Fe(s) + CuSO4(aq) = FeSo4(aq) + Cu(s)
Carbon + Iron(III) Oxide = Carbon Dioxide + Iron
3C(s) + 2Fe2O3(s) = 3CO2(g) + 4Fe(l)

13) Why do displacement reactions happen ?
A more reactive metal forms stronger bonds with non-metals.

14) What is Electrolysis ?