Name the substance oxidised, substance reduced, oxidising agent and reducing agent in the following reaction: 

${\mathrm{CuSO}}_4+\mathrm{Zn}\to \mathrm{Cu}+{\mathrm{ZnSO}}_4$

Name the substance oxidised, substance reduced, oxidising agent and reducing agent in the following reaction: 

$\mathrm{Cu}+2{\mathrm{AgNO}}_3\to \mathrm{Cu}{\left({\mathrm{NO}}_3\right)}_2+2\mathrm{Ag}$

In electrolytic decomposition reactions of water, why few drops of sulphuric acid are added to the water? 

In electrolytic decomposition reactions of water, name the gas produced at anode and cathode.

A blue coloured inorganic compound when heated with ${\mathrm{H}}_2\mathrm{S}$, gives black precipitate and an aqueous solution of sulphuric acid. Identify the compound. Give your answer with a balanced chemical equation. 

What is an oxidation reaction? Give an example of oxidation reaction. Is oxidation an endothermic or an exothermic reaction? 

Classify the following reaction as a combination, decomposition, displacement or double displacement reaction: 

${\mathrm{CaCO}}_3\left(\mathrm{s}\right)\stackrel{\mathrm{Heat}}{\to }\mathrm{CaO}\left(\mathrm{s}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)$

Classify the following reaction as a combination, decomposition, displacement or double displacement reaction:

$\mathrm{CaO}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to \mathrm{Ca}{\left(\mathrm{OH}\right)}_2\left(\mathrm{aq}\right)$