For the reaction $SO_2 + 2H_2S \to 3S + 2H_2O$,which option represents twice the equivalent weight of the oxidizing agent?

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$NaH_{(s)} + H_2O_{(l)} \longrightarrow NaOH_{(aq)} + H_{2(g)} \uparrow$

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$BaSO_3(s) + H_2SO_4(aq) \longrightarrow BaSO_4(s) + SO_2(g) + H_2O(l)$

Identify whether the following reactions act as oxidation or reduction processes:
$(i) \ S + 6HNO_3 \to H_2SO_4 + 6NO_2 + 2H_2O$
$(ii) \ 2K + Br_2 \to 2KBr$

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$Ca(OH)_2 + CO_2 \longrightarrow CaCO_3 \downarrow + H_2O$

In the reaction of gold with aqua regia,the oxidation state of Nitrogen changes from