The reaction of $Na_2S_2O_3$ with iodine gives

$10 \, \text{mole}$ of ferric oxalate is oxidised by $x \, \text{mole}$ of $MnO_4^-$ in acidic medium. The value of $x$ is

Equivalent weight of $H_3PO_2$ when it disproportionates into $PH_3$ and $H_3PO_3$ is:

Assign $A, B, C, D$ from the given type of reaction.
$PbCrO_4 \downarrow + 4NaOH \,(Excess) \longrightarrow Na_2[Pb(OH)_4] + Na_2CrO_4$

In which of the following reactions, chlorine acts as an oxidising agent?
$(i)$ $CH_3CH_2OH + Cl_2 \longrightarrow CH_3CHO + HCl$
(ii) $CH_3CHO + Cl_2 \longrightarrow CCl_3CHO + HCl$
(iii) $CH_4 + Cl_2 \stackrel{hv}{\longrightarrow} CH_3Cl + HCl$
The correct answer is

Which one of the following reactions is not an example of a redox reaction?