Răspuns:
a)
2 KMnO4 + 6 HCI+ 5 H2S → 2KCl + 2MnCl2 +5S + 8 H2O
2 Mn VII + 10 e - → 2 Mn II (reducere)
5 S -II - 10 e - → 5 S 0 (oxidare)
K Mn O 4 agent oxidant
H 2 S agent reducator
b)
2 K MnO4 + 10KI+ 8 H2SO4→ 2MnSO4 + 6KSO4 + 5I2+ 8 H2O
2 Mn VII + 10 e - → 2 Mn II (reducere)
10 I -I - 10 e - → 10 I 0 (oxidare)
K Mn O 4 agent oxidant
K I agent reducător.
