Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$BaSO_3(s) + H_2SO_4(aq) \longrightarrow BaSO_4(s) + SO_2(g) + H_2O(l)$

Given below are two statements.
Statement-$I$: In the decomposition of potassium chlorate,$Cl$ is reduced.
Statement-$II$: Reaction of $Na$ with $O_2$ to form $Na_2O$ is a redox reaction.
The correct answer is

Which of the following is oxidised by $SO_2$?

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$Pb(CH_3COO)_2 + Na_2CrO_4 \longrightarrow PbCrO_4 \downarrow + 2CH_3COONa$

Whenever a reaction between an oxidising agent and a reducing agent is carried out,a compound of lower oxidation state is formed if the reducing agent is in excess and a compound of higher oxidation state is formed if the oxidising agent is in excess. Justify this statement giving three illustrations.

Potassium permanganate works as an oxidising agent both in acidic and basic medium. In both states,the products obtained by $KMnO_4$ are respectively: