Question

1. Sort the following manganese compounds by whether the cation is manganese(II) or manganese(III).

Answer 1

In order to determine the state of the manganese ion, we will look at the anion bonded to it.
MnN, N = -3 so Mn(III)
MnO, O = -2 so Mn(II)
MnBr2, Br = -2 so Mn(II)
Mn2S3, S = -2 so Mn(III)
Mn3P2, P = -3 so Mn(II)
MnI3, I = -3 so Mn(II)

2.
For this question we will have to check the number of protons of each element from the periodic table. After this, we will remove or add electrons until the desired charge is attained (charge is difference between number of protons and electrons) since the number of protons does not change.

K+: protons = 19, electrons = 18
Cl-: protons = 17, electrons = 18
Fe+2: protons = 26, electrons = 24