Uploaded by Gemma Morrison

Reactions of metals

Reactions of metals
Reactive metals + acid …
How metals react with acid tell you about their reactivity...
Metal + Acid → Salt + Hydrogen
• Some metals react with acids to produce a salt and a
hydrogen gas.
• You can use the reactions of different metals with dilute
acid to work out how reactive they are.
• The more reactive the metal is, the faster the reaction will
go – very reactive metals (e.g. sodium) react explosively.
• You can carry out a practical to investigate the differences
in reactivity of a variety of different metals by using their
reaction with acids.
• Set up 3x boiling tubes and fill them with equal volumes of
dilute hydrochloric or dilute sulfuric acid.
• Place the pieces of magnesium, zinc and iron in separate
test tubes – make sure that the size and shape of the metal
pieces is the same.
• The speed of the reaction is indicated by the rate at which
the bubbles of hydrogen are given off.
• The hydrogen is confirmed by the burning splint test. The
magnesium should give the loudest ‘squeaky pop’ as it has
the most vigorous reaction producing the most hydrogen
Reacting metals with dilute acid:
• Metals above hydrogen in the reactivity series will react
with acid to make a salt and hydrogen.
• The metals below hydrogen in the reactivity series do
not react with acids.
• The reaction becomes less and less exciting as you go
down the series.
• All acids contain hydrogen so the hydrogen here comes
from the acid.
More reactive metals react more violently…
React violently with dilute
acids (likely to explode)
React fairly well with dilute
Do not react with dilute
The lower the reactivity, the less likely it is for a reaction to
Zinc + Sulfuric acid → Zinc sulfate + hydrogen
The zinc takes the place of the hydrogen in the reaction as it
is more reactive than the hydrogen.
Sodium + hydrochloric acid acid → sodium chloride +
The sodium takes the place of the hydrogen in the reaction
as it is more reactive than the hydrogen.
Metals + water…
The reactions of metal and water also shown the reactivity of
the metals.
Metal + Water → Metal hydroxide + Hydrogen
(Or: less reactive metal + steam → metal oxide + Hydrogen)
Very reactive metals like potassium, sodium, lithium and
calcium will all react vigorously with water.
The amount of energy given out by the reaction increases the
reactivity of the metal. The reaction with potassium gives out
enough energy to ignite hydrogen.
Less reactive metals like magnesium, zinc and iron won’t
react much with cold water, but they will react with steam.
You could show this in the lab using the experiment…
Copper will not react with either water or steam.