When a manganous salt is fused with a mixture of $KNO_3$ and solid $NaOH$,the oxidation number of $Mn$ changes from $+2$ to:

Assign $A, B, C, D$ from the given type of reaction.
$AgNO_3 \,(Solution) + NaF \,(Solution) \longrightarrow$ No reaction

If stoichiometric quantities of a $KMnO_4$ and $K_2Cr_2O_7$ mixture are added for the oxidation of $Fe^{2+}$ to $Fe^{3+}$ in an acidic medium,then $Fe^{2+}$ will be oxidized:

How many moles of $H_2SO_3$ are required to reduce one mole of $KMnO_4$ in an acidic medium?

Which of the following are non-metal displacement reactions?
$(A)$ $Ca_{(s)} + 2 H_2 O_{(l)} \longrightarrow Ca(OH)_{2(aq)} + H_{2(g)}$
$(B)$ $V_2 O_{5(s)} + 5 Ca_{(s)} \stackrel{\Delta}{\longrightarrow} 2 V_{(s)} + 5 CaO_{(s)}$
$(C)$ $2 Fe_{(s)} + 3 H_2 O_{(g)} \stackrel{\Delta}{\longrightarrow} Fe_2 O_{3(s)} + 3 H_{2(g)}$
$(D)$ $Cr_2 O_{3(s)} + 2 Al_{(s)} \stackrel{\Delta}{\longrightarrow} Al_2 O_{3(s)} + 2 Cr_{(s)}$

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$MnS(s) + 2HCl(aq) \longrightarrow MnCl_2(aq) + H_2S(g)$