Answer:
The charge of cobalt in the salt is + 2.
Explanation:
The charge of the salt = 0 . This is because it is neutral.
Charge of cobalt = ?
Charge of oxygen = -2 (This is a constant value, it is -2 only in peroxides)
Charge of salt = Charge of cobalt + Charge of oxygen
0 = x + (-2)
x = + 2
The charge of cobalt in the salt is + 2.
