The number of moles of acidified $KMnO_4$ required to convert one mole of sulphite ion into sulphate ion is

Justify that the reaction: $2 Na ( s ) + H_2 ( g ) \rightarrow 2 NaH ( s )$ is a redox change.

Which of the following solutions will turn violet when a drop of lime juice is added to it?

Which of the following is a redox reaction?

Assign $A, B, C, D$ from the given types of reactions:
$A$: Disproportionation reaction.
$B$: Comproportionation reaction.
$C$: Either intermolecular redox reaction or displacement reaction.
$D$: Either thermal combination redox reaction or thermal decomposition redox reaction.
Reaction: $MnO_4^- + H^+ + Br^- \longrightarrow Mn^{2+}(aq.) + Br_2 \uparrow$

Phenolphthalein does not act as an indicator for the titration between