Assign $A, B, C, D$ for the given type of reaction: $CuSO_4$ (solution) + $ZnCl_2$ (solution) $\longrightarrow$ No reaction.

Identify whether the following reactions act as oxidation or reduction processes:
$(i) \ S + 6HNO_3 \to H_2SO_4 + 6NO_2 + 2H_2O$
$(ii) \ 2K + Br_2 \to 2KBr$

Metal sulphate $(A) \xrightarrow{\text{Heat}}$ Oxide $(B) +$ Gas $(C) +$ Gas $(D) \xrightarrow{Cr_2O_7^{2-} / H^{+}}$ Green solution $\xrightarrow[\text{Excess}]{Na_2O_2}$ Yellow solution $(E)$. Compound $A, B, C, D$ and $E$ are respectively:

When mercury $(II)$ chloride is treated with excess of $SnCl_2$,the products obtained are

The oxidation state of manganese in the product obtained in a reaction of potassium permanganate and hydrogen peroxide in basic medium is $.....$

$H_2S$ ($5$ moles) reacts completely with acidified aqueous potassium permanganate solution. In this reaction,the number of moles of water produced is $x$,and the number of moles of electrons involved is $y$. The value of $(x+y)$ is. . . . . .