#1
[tex]\\ \tt\bull\rightarrowtail Cu^{2+}+NO_2\longrightarrow Cu(NO_2)_2[/tex]
#2
[tex]\\ \tt\bull\rightarrowtail Cu^{2+}+SiO_3^{2-}\longrightarrow CuSiO_3[/tex]
#3
[tex]\\ \tt\bull\rightarrowtail Cu^{2+}+HSO^{4-}\longrightarrow Cu_4HSO_2[/tex]
#4
[tex]\\ \tt\bull\rightarrowtail Cu^{2+}+PO_4^{3-}\longrightarrow Cu_3(PO_4)_2[/tex]
