Giải
a) \(CuS{O_4} + N{a_2}S \to CuS \downarrow + N{a_2}S{O_4}\)
\(\left( {C{u^{2 + }} + {S^{2 - }} \to CuS \downarrow } \right)\)
b) \(CdS{O_4} + N{a_2}S \to CdS \downarrow + N{a_2}S{O_4}\)
\(\left( {C{d^{2 + }} + {S^{2 - }} \to CdS \downarrow } \right)\)
c) \(MnS{O_4} + N{a_2}S \to MnS \downarrow + N{a_2}S{O_4}\)
\(\left( {M{n^{2 + }} + {S^{2 - }} \to MnS \downarrow } \right)\)
d) \(ZnS{O_4} + N{a_2}S \to ZnS \downarrow + N{a_2}S{O_4}\)
\(\left( {Z{n^{2 + }} + {S^{2 - }} \to ZnS \downarrow } \right)\)
e) \(FeS{O_4} + N{a_2}S \to FeS \downarrow + N{a_2}S{O_4}\)
\(\left( {F{e^{2 + }} + {S^{2 - }} \to FeS \downarrow } \right)\)
