In the reaction $A^{-n_2} + x e^- \to A^{-n_1}$,the value of $x$ is:

$KMnO_4$ oxidises oxalic acid in acidic medium. The number of $CO_2$ molecules produced per mole of $KMnO_4$ is

What is $A$ in the following reaction $2Fe^{3+}_{(aq)} + Sn^{2+}_{(aq)} \to 2Fe^{2+}_{(aq)} + A$?

For the reaction: $KClO_3 + 6FeSO_4 + 3H_2SO_4 \to KCl + 3Fe_2(SO_4)_3 + 3H_2O$. Which of the following statements is true $(T)$ or false $(F)$ regarding the nature of the reaction? The reaction is complex.

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$MnO_2 + 2NaCl + 2H_2SO_4 \longrightarrow MnSO_4 + Na_2SO_4 + 2H_2O + Cl_2 \uparrow$

Which of the following is a redox reaction?