$KMnO_4$ oxidises oxalic acid in acidic medium. The number of $CO_2$ molecules produced per mole of $KMnO_4$ is

Which of the following reactions is a redox reaction?

Observe the following reaction: $I_2 + 10 HNO_3 \rightarrow 2 HIO_3 + 10 NO_2 + 4 H_2O$. The equivalent weight of $HNO_3$ is (molar mass of $HNO_3 = M$).

The $Mn^{3+}$ ion is unstable in solution and undergoes disproportionation to give $Mn^{2+}$,$MnO_2$ and $H^{+}$ ion. Write a balanced ionic equation for the reaction.

The equivalent weight of ${S_2O_3^{2-}}$ in the reaction where it acts as a reductant is ...... . ${2S_2O_3^{2-} + I_2 \rightarrow S_4O_6^{2-} + 2I^-}$

Assign $A, B, C, D$ from given type of reaction.
$Na_{(s)} + H_2O_{(l)} \xrightarrow{R.T.} NaOH + H_2 \uparrow $