K2Cr2O7/H+\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7} / \mathrm{H}^{+}K2Cr2O7/H+
2,4−DNP2,4-D N P2,4−DNP
[Ag(NH3)2]+\left[\mathrm{Ag}\left(\mathrm{NH}_{3}\right)_{2}\right]^{+}[Ag(NH3)2]+
PCl3\mathrm{PCl}_{3}PCl3