Assign $A, B, C, D$ from the given type of reaction.
$KMnO_4 + NaNO_3 \longrightarrow$ No reaction

In the following reactions $(i)$ $MnO_2 + 4 HCl \rightarrow$ and $(ii)$ $2 KMnO_4 + 16 HCl \rightarrow$,the number of moles of chlorine gas released respectively are

Justify that the following reactions are redox reactions:
$(a) \ CuO_{(s)} + H_{2(g)} \to Cu_{(s)} + H_2O_{(g)}$
$(b) \ Fe_2O_{3(s)} + 3CO_{(g)} \to 2Fe_{(s)} + 3CO_{2(g)}$
$(c) \ 4BCl_{3(g)} + 3LiAlH_{4(s)} \to 2B_2H_{6(g)} + 3LiCl_{(s)} + 3AlCl_{3(s)}$
$(d) \ 2K_{(s)} + F_{2(g)} \to 2K^+F^-_{(s)}$
$(e) \ 4NH_{3(g)} + 5O_{2(g)} \to 4NO_{(g)} + 6H_2O_{(g)}$

If zinc pieces are added to yellow $FeCl_3$ solution,it turns to very light green. It is because

$Na_2S_2O_3$ is

Which of the following are redox changes?
$(i)$ Hydrolysis of $XeF_2$
$(ii)$ Thermal decomposition of $Ag_2CO_3$
$(iii)$ Reaction of $Al$ with $NaOH$
$(iv)$ Hydrolysis of $PCl_5$
$(v)$ Reaction of $NaCl$ with conc. $H_2SO_4$
Correct options are: