Some metals are chemically very reactive where as other metals are less reactive .
- the arrangement of metal in a vertical column in the order of decreasing reactivity is called activity series of metals.
a) Reaction with oxygen :
Metals react with oxygen under different condition to form metallic jioxides (basic nature). These metallic oxides react with water to form bases
e.g. magnesium burns in the air to form magnesium oxides . these oxides react with water to form magnesium hydroxides
b) reaction with water : metals react with water to form metal hydroxides and hydrogen gas . e.g .1) sodium reacts with water to form sodium hydroxides and hydrogen gas
2 ) Magnesium react with water to form magnesium hydroxides and hydrogen.
3) iron react wit water is slowly.
c) Reaction with acids:
Metals react with dilute acids to form their salts and hydrogen gas. and produce pop sound when burning candle is brought near to the test tube mouth.
e..g zinc react with dilute hydrochloric acids to form zinc chlorides and hydrogen gas.
• Metals ( copper, silver, gold and platinum ) do not react with dilute acids
because they are less reactive than hydrogen.
d) Reaction with base :
Most of the metals does not react with base but some metals react with base.
Like aluminum., Zinc , lead react with base
Metals react with base to form complex salt and hydrogen gas
Examples:
• All metals do not react with bases to form salts and hydrogen.
Questions:
1) Give the name of most reactive metal
– Potassium (K)
2) Which gas evolved when metals reacts with base?
– Hydrogen gas
3) Which is the less reactive metal
-gold is the less reactive metal.
4) what is the nature of metal oxides?
– metal oxides are generally in basic nature
5) what happen when metal react with water ?
– metal react with water to produce their hydroxides and hydrogen gas
6) how do metal react with base ? Give its example ?
– most of the metals do not react with base but some metals like aluminum, lead , zinc react with strong base like sodium hydroxide and form salt and hydrogen.
e.g. Zinc react with sodium hydroxide to form sodium zincate and hydrogen gas
7) What happen when iron react with oxygen ?
– Iron react with oxygen and form iron oxides.
8) what is mean by activity series of metals ?
The arrangement of metal in the descending order of their reactivity is called as activity series of metals.
In this reactivity series more reactive metal at the top and least reactive metal are at bottom are placed .the metal are arrange by their reactivity order.