The reaction of an aqueous acidic solution of NiCl2 with NaNO2 gives a green precipitate Z, and with KSCN, a purple-colored compound W. Compounds Z and W, respectively, are:
1
Na3Ni(NO2)6 and Ni(SCN)2
2
Na4Ni(NO2)6 and K2Ni(SCN)4
3
Na4Ni(NO2)6 and Ni(SCN)2
4
Na3Ni(NO2)6 and K2Ni(SCN)4