Zusammenfassung der Ressource
reactions of metals and the reactivity series
- 90 elements that occur naturally
- 70 of these are metals
- only a few are in common use
- Making salts- acid plus base
- a base is any compound that can neutralise an acid
- Examples:
metal oxide - copper oxide
metal hydroxide - sodium hydroxide
metal carbonates - magnesium carbonate
metal hydrogen - calcium hydrogen
ammonia
- Acid + base -------- salt + water
- sulphuric acid + copper oxide -------- copper sulphate + water
- warm the acid + base
then when it is cool,
filter the mixture. boil
the filtrate and leave
the remaining solution
in a petri dish the
water will evaporate
and leave salt crystals
behind
- Making salts - acid plus carbonate
- acid + carbonate -------- salt + carbon dioxide + water
- nitric acid + magnesium carbonate -------- magnesium nitrate + carbon dioxide + water
- keep adding the
magnesium carbonate
until no more fizzing
occurs. filter out the
remaining powder that
has not reacted, pour
it into a petri dish and
leave it to evaporate.
long thin salt crystals
of will form and be left
in the petri dish.
- Action of Acid on metals
- to test the effect of hydrochloric acid and sulphuric acid on 4 different metals
- Iron
Copper
Zinc
Magnesium
- Sulphuric acid
- created more
hydrogen than the
hydrochloric acid.
- produced heat with magnesium
- Hydrochloric acid
- produced heat with magnesium
- the most reactive metals produce hydrogen
- with this information we can make a reactive series
- magnesium (Mg) - produced hydrogen with acid
- Zinc (Zn) - slow fizzing reaction with acid
- Iron (Fe) - very slow fizzing reaction with acid
- Copper (Cu) - no reaction with acid
- Making Salts - acid plus metals
- acid + metal -------- salt + hydrogen
- hydrochloric acid + zinc -------- zinc chloride + hydrogen
- leave the metal in a test
tube full of the acid until
a further reaction has
finished. when it is
heated gently (bunsen
flame) salt crystals will
form and give off the gas
hydrogen
- all acids react in the same way when they are tested in these ways
- action with magnesium: fizzing, turning milky
- action with copper oxide: strong fizzing, turned blue
- action with magnesium carbonate: fizzing, turning milky
- pH: red (1)
- Rusting of Iron
- rusting is the oxidation of iron to form iron oxide
- this reaction occurs slowly in damp air
- iron + oxygen + water vapour -------- iron oxide (rust)
- when water and oxygen are present rusting occurs
- when oxygen and/or water is removed, the rusting is reduced
- Extraction of Copper
- all of the copper on the earths crust is found as copper compounds or ores.
- one of the copper ores is malachite. there are three stages in extracting the copper from malachite.
- STAGE 1
- turn the malachite into copper oxide
- THERMAL DECOMPOSITION
- copper carbonate --heat-- copper oxide + carbon dioxide
- when it is heated, carbon dioxide will be let out - keep reacting
until no more carbon dioxide is produced
- black copper oxide and carbon dioxide gas were formed.
- STAGE 2
- change the copper oxide into copper sulphate
- copper oxide is a base. it dissolves in
an acid to make a neutral solution that
contains a salt.
- acid + base -------- salt + water
- sulphuric acid + copper oxide -------- copper sulphate + water
- heat the mixture of copper oxide and
sulphuric acid until it reaches 70 oC
and then filter off the unreacted copper
oxide and keep the copper sulphate
solution to use in stage 3.
- heating the copper oxide
withe the sulphuric acid
formed the blue copper
sulphate solution. the excess
copper oxide was removed
by filtration
- STAGE 3
- remove the copper from the copper sulphate
- compounds can be broken down using electricity
(electrolysis)
- when copper sulphate is electrolysed,
it breaks down to form copper metal,
sulphuric acid and oxygen
- copper sulphate + water --electrolysis-- copper + sulphuric acid + oxygen
- when an electric current is passed through the
solution for about 5 minutes the compound
decomposes
- therefore electrolysis can be used to extract
metals from their ores.
- Reactivity of metals
- Some metals are more reactive than others.
- The alkali metals (group 1) are highly reactive.
- when reacted with water, they produce hydrogen gas.
- metal + water -------- alkali + hydrogen
- more reactive metals displace less reactive metals from their compounds.
- for example, iron is more reactive than copper.
- Iron + copper sulphate -------- iron sulphate + copper
- THIS IS CALLED A DISPLACEMENT REACTION
- potassium
sodium
lithium
calcium
magnesium
aluminium
carbon (C)
zinc (Zn)
iron (Fe)
copper
silver(Ag)
gold
- This is a Reactive Series
- the elements below
carbon can be isolated by
heating their ore with
carbon. The carbon
displaces the metal from
its ore.