Interactive Chemistry Worksheets for Students |
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What is produced by the action of acids with active metals?
Active metals react with acids to produce hydrogen gas and a salt.
The general equation of this type of chemical reaction is
Active metal + acid 
salt + hydrogen gas
This is an example of a single displacement reaction. One element (the active metal) displaces another in a compound (the acid). Active metals displace the hydrogen from acids producing hydrogen gas.
The two most common acids used are hydrochloric acid, HCl and sulfuric acid, H2SO4
Example.
Magnesium + sulfuric acid magnesium sulfate + hydrogen
Mg + H2SO4 MgSO4 + H2
The magnesium displaces the hydrogen from the acid. It's like calling for a single substitution during a game of basketball. Mg goes on the court and H2 comes off.
What is the activity series of metals?
Metals have different chemical reactivities.
The activity series of metals is the arrangement of metals in order of chemical reactivity from most to least active.
Most active metals
Magnesium
Zinc
Iron
Lead
------------ Metals above this line can displace hydrogen from acids.
Copper
Silver
Gold
Least active metals
What is an active metal?
Active metals are metals that can displace the hydrogen ions, H+ from acids to produce hydrogen gas.
Metals like magnesium, zinc and iron are common active metals.
The reaction of lead with acids is slow.
Copper, silver and gold are not active enough to react with these acids.
Examples of acid metal reactions
General equation
Active metal + acid salt + hydrogen gas
1. Zinc + sulfuric acid zinc sulfate + hydrogen gas
Zn + H2SO4 ZnSO4 + H2
2. Magnesium + hydrochloric acid magnesium chloride + hydrogen gas
Mg + 2HCl MgCl2 + H2
3. Iron + sulfuric acid Iron(II) sulfate + hydrogen gas
Fe + H2SO4 FeSO4 + H2
Advanced reactions of acids and metals
A. Nitric acid is an oxidising acid.
Nitric acid reacts with copper and produces different products according to its concentration.
1. Copper + nitric acid copper nitrate + nitrogen dioxide + water
Cu + 4HNO3 Cu(NO3)2 + 2NO2 + 2H2O
2. Copper + nitric acid copper nitrate + nitrogen monoxide + water
3Cu + 8HNO3 3Cu(NO3)2 + 2NO + 4H2O
B. Concentrated sulfuric acid is an oxidising acid.
Concentrated sulfuric acid reacts with copper according to the following equation
3. Copper + concentrated sulfuric acid copper sulfate + sulfur dioxide + water
Cu + 2H2SO4 CuSO4 + SO2 + 2H2O