When $10 \, mL$ of an aqueous solution of $KMnO_{4}$ was titrated in acidic medium,an equal volume of $0.1 \, M$ aqueous solution of ferrous sulphate was required for complete discharge of colour. The strength of $KMnO_{4}$ in grams per litre is $...... \times 10^{-2}$. (Nearest integer)
[Atomic mass of $K=39, Mn=55, O=16$]

Which of the following reactions is not a redox reaction?

Hot concentrated sulphuric acid is a moderately strong oxidizing agent. Which of the following reactions does not show oxidizing behaviour?

Calculate the millimoles of $SeO_3^{2-}$ in solution on the basis of following data: $70 \ mL$ of $\frac{M}{60}$ solution of $KBrO_3$ was added to $SeO_3^{2-}$ solution. The bromine evolved was removed by boiling and excess of $KBrO_3$ was back titrated with $12.5 \ mL$ of $\frac{M}{25}$ solution of $NaAsO_2$. The reactions are given below.
$I. \ SeO_3^{2-} + BrO_3^{-} + H^{+} \to SeO_4^{2-} + Br_2 + H_2O$
$II. \ BrO_3^{-} + AsO_2^{-} + H_2O \to Br^{-} + AsO_4^{3-} + H^{+}$

Why do the following reactions proceed differently? $Pb_{3}O_{4} + 8HCl \rightarrow 3PbCl_{2} + Cl_{2} + 4H_{2}O$ and $Pb_{3}O_{4} + 4HNO_{3} \rightarrow 2Pb(NO_{3})_{2} + PbO_{2} + 2H_{2}O$

Assign $A, B, C, D$ for the given type of reaction:
$Mn(NO_3)_2 + 2NaOH \longrightarrow Mn(OH)_2 \downarrow + 2NaNO_3$