Use a reference listing standard half-reaction potentials to select the most likely identity of your unknown solution.
1.
Nickel(II) chloride, NiCl2 (aq)
2.
Iron(II) chloride, FeCl2 (aq)
3.
Silver chloride, AgNO3 (aq)
4.
Manganese(II) bromide, MnBr2 (aq)
5.
Cobalt(II) chloride, CoCl3 (aq)
6.
Chromium(III) chloride, CrCl3 (aq)