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

Acidified $KMnO_4$ can be decolourised by

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$Na_2CO_3 + 2AgNO_3 \longrightarrow Ag_2CO_3(s) + 2NaNO_3(aq)$

Consider the reactions:
$(a)$ $6 CO_{2(g)} + 6 H_{2}O_{(l)} \rightarrow C_{6}H_{12}O_{6(aq)} + 6 O_{2(g)}$
$(b)$ $O_{3(g)} + H_{2}O_{2(l)} \rightarrow H_{2}O_{(l)} + 2 O_{2(g)}$
Why is it more appropriate to write these reactions as:
$(a)$ $6 CO_{2(g)} + 12 H_{2}O_{(l)} \rightarrow C_{6}H_{12}O_{6(aq)} + 6 H_{2}O_{(l)} + 6 O_{2(g)}$
$(b)$ $O_{3(g)} + H_{2}O_{2(l)} \rightarrow H_{2}O_{(l)} + O_{2(g)} + O_{2(g)}$
Also,suggest a technique to investigate the path of the above $(a)$ and $(b)$ redox reactions.

Assign $A, B, C, D$ from the given type of reaction.
$CrCl_3$ $(aq)$ + $ZnSO_4$ $(aq)$ $\longrightarrow$ No reaction

Which of the following is not an oxidation-reduction reaction?