3 CH3CH2OH (aq) + 2 KMnO4 (aq) → 3 CH3CHO (aq) + 2 MnO2 (s) + 2 KOH (aq) + 2 H2O (l)
This is an oxidation-reduction (redox) reaction:
2 MnVII + 6 e- → 2 MnIV (reduction)
3 C-II - 9 e- → 3 CI (oxidation)
3 C-II + 3 e- → 3 C-III (reduction)
This is a precipitation reaction: MnO2 is the formed precipitate.