Ferrous sulphate on strong heating gives:

In order to oxidize a mixture of one mole of each of $FeC_2O_4$,$Fe_2(C_2O_4)_3$,$FeSO_4$ and $Fe_2(SO_4)_3$ in acidic medium,the number of moles of $KMnO_4$ required is

In which of the following conversions does a blue colour appear?

Assign $A, B, C, D$ from given type of reaction.
$2KI + CuSO_4 \longrightarrow CuI \downarrow + \frac{1}{2}I_2 + K_2SO_4$

In which of the following reactions is there no change in valency?

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