Question

what is reactivity series? how does the reactivity series of metals help in predicting the relative activities of various metals?

Answer 1

The arrangement of metals according to their reactivity is called activity series of metals
Activity series of metals in order of decreasing reactivity:
Potassium
Sodium
Calcium
Magnesium
Aluminium
Zinc
Iron
Nickel
Tin
Lead
Hydrogen
Copper
Mercury
Silver
Gold
Platinum
Active metals like potassium,sodium and calcium react vigorously Rest metals till iron react till some extent Metals after hydrogen donot react mostly

Answer 2

Answer:

1 ) .Reactivity series :

It is series of decreasing order of metals' reactivity. Hydrogen is place in middle of series. Above hydrogen metals are more reactive in nature below are less. Metal which is more reactive it displaces a less reactive metal from its salt solution.

2 ) .

In order to obtaining a metal from its  oxides for metals in the middle of the reactivity series then metals towards oxides of such metals can be reduced with coke (carbon) which acts as a reducing agent.

For instance :

2 Fe₂O₃ + 3 C  ⇒ 4 Fe + 3 CO₂.

In order to obtaining a metal from its  oxides for metals in the high of the reactivity series their oxides are reduced to metals by the process of electrolysis

For instance :

Electrolysis of sodium chloride :

Na⁺ + e⁻  ⇒ Na   [ At cathode ]

2 Cl⁻ ⇒ Cl₂ + 2 e⁻   [ At anode ]