Write the different chemical processes for obtaning a metal from it's oxide in the middle of the reactivity series and metal towards the top of reactivity series . write one example with each.
Answers
The metals likrFe,Zn,Pb,Cu are moderately reactive.The metal sulphides and carbonates must be cnvertes to metal oxide.
Roasting:process of convertimg the sulphide ores into oxides in the presence of air
Eg:- 2ZnS+3O2-------2ZnO +2SO2
Calcination:-process of converting carbonate ore into oxides in the absemce of air.
Eg:-ZnCO3---------- ZnO+CO 2
metal oxides are then reduced to metals by using reducing agent like carbon.
Eg:- ZnO+ C------- ZnO+C
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 ]