A for precipitate formation reaction.
B for precipitate dissolution reaction.
C for precipitate exchange reaction.
D for no reaction.
${P_4} + NaOH \longrightarrow P{H_3} \uparrow + Na{H_2}P{O_2}$
આપેલ : $2 Cu ^{2+}+4 I ^{-} \rightarrow Cu _{2} I _{2}+ I _{2}$
$I _{2}+2 S _{2} O _{3}{ }^{2-} \rightarrow 2 I ^{-}+ S _{4} O _{6}{ }^{2-}$