Make a diagram of the electrolysis of chromium nitrate (3).

Chromium nitrate dissociates into 4 elements, a chromium cation and three nitro groups, we write the reaction:
Cr (NO3) 3 => Cr (3+) + 3NO3 (-)
During electrolysis, positively charged cations (i.e., chromium cations) tend to the negatively charged cathode, while negatively charged anions tend to the positive anode.
The reduction potential of chromium from aqueous solutions is E = -0.74 V
The decomposition potential of water is E = -0.82 V
The chromium potential is less negative, so chromium will be the first to recover from water than its decomposition will take place.
Oxygenated anions are not oxidized at the anode! There will be decomposition of water.
Let’s write cathodic and anodic reactions separately:
К (-): Cr (3+) + 3e = Cr
A (+): 2H2O – 4e = O2 + 4H (+)
Overall response:
4Cr (NO3) 3 + 6H2O = 4Cr + 12HNO3 + 3O2