Answer the following question:
What is the difference between calcination and roasting?
Calcination : Heating of the ore in the absence of air to remove volatile impurities and make the ore porous.
Eg. ZnCO3 +heat --> ZnO +CO2
Roasting: heating the ore in free supply of air, so that non-metallic impurities can get oxidised and escape a gases
2ZnS+3O2----> 2ZnO +2SO2
Differentiate between electrical conductivity of copper sulphate solution and copper metal.
Given a reason as to why?
The electrolysis of acidulated water is considered to be an example of catalysis.
Answer the following question:
Write the chemical formulae of one main one of iron and aluminium.
Answer the following question:
Name a metal which is found abundantly in the earth’s crust.
What would you observe in the following case?
When carbon monoxide is passed over heated copper oxide.
Answer the following question:
Write the constituents of electrolyte for the extraction of aluminium
During the electrolysis of copper (II) sulphate solution using platinum as cathode and carbon as anode:
i) What do you observe at the cathode and at the anode?
(ii) what change is noticed in the electrolyte?
(iii) write the reaction at the cathode and at the anode?
Write the balanced chemical equation for each of the following reaction:
Sodium thiosulphate is reacted with dilute hydrochloric acid.
