Reactivity Tests
Chemistry: AQA GCSE Higher, topic 4.2.6
Reactions of Metals
Reactive metals with water
- Potassium, sodium and lithium all react quickly with cold water to produce a metal hydroxide and hydrogen gas.
Reactive metals with water cont.
- Potassium is the most reactive so reacts very quickly. The hydrogen produced ignites instantly and the metal also sets alight, sparking and burning with a lilac flame.
- Sodium fizzes rapidly and melts to form a ball that moves around on the water surface.
- Lithium fizzes steadily and floats, becoming smaller until it eventually disappears.
Reactions with dilute acids
- Most metals react with dilute acids to produce a salt and hydrogen gas.
- The exceptions are copper, silver, gold and platinum. They are not reactive enough to react.
- The metals that react with dilute acids but not cold water are magnesium, aluminium, zinc, iron and lead (iron and lead react slowly).
Metal extraction
- Most metals are only found as compounds because the metal has reacted with other elements in the past.
- Because of this, the metal has to be extracted from the ore where the metal compound is found.
Extraction with carbon
- Metals that are less reactive than carbon can be extracted from their oxides by reducing with carbon.
- Carbon is used because it is cheap and abundant.
- In the reduction, the metal oxide loses oxygen to form a pure metal.
- Reduction with carbon normally involves heating the metal oxide in the presence of the carbon, which is often used in the form of coal.
Test yourself on Reactivity Tests
Select the correct statement for each pair
Why is carbon used to extract metals from their oxides?
Select the correct statement for each pair
A metal oxide is heated with carbon and loses its oxygen, leaving behind a pure metal. What is this process called?