Which one of the 6 reactions involving metal ions represents a redox reaction? Which species is oxidized (write the element and the oxidation number before and after oxidation)? Which species is reduced (write the element and the oxidation number before and after reduction)?

These are the following 6 reactions:

1) Ag+ (aq) + HCl (aq) AgCl (s, white) + H+ (aq)

2) AgCl (s) + 2 NH3 (aq) Ag(NH3)2+ (aq) + Cl (aq)

3) Fe3+ (aq) + 3 NH3 (aq) + 3 H2O (l) Fe(OH)3 (s) + 3 NH4+ (aq)

4) Fe3+ (aq) + SCN (aq) Fe(SCN)2+ (aq, red-brown)

5) 4 Fe3+ (aq) + 3 K4[Fe(CN)6] (aq) Fe4[Fe(CN)6]3 (s, blue) + 12 K+

6) Co2+ (aq) + 7 NO2 (aq) + 3 K+ (aq) + 2 H+ (aq) NO (g) + H2O (l) + K3[Co(NO2)6] (s, yellow)

I am thinking it might be #2 with N being oxidized and Ag being reduced but I am not sure if I am correct.