Question

Analysis shows that nickel oxide has the formula $N{i}_{0.98}{O}_{{1.100}^{.}}$ What fraction of nickel exist as $N{i}^{2+}andN{i}^{3+}$ ions ?

Answer 1

• The ratio of Ni and O atoms in pure nickel oxide (NiO) = 1 : 1 Let x be the number of Ni (II) atoms replaced by Ni (III) atoms in the oxide.

• $\therefore$ Number of Ni (III) atoms present = (0.98 - x)

• Since, the oxide is neutral in nature,

Total charge on Ni atoms = Charge on oxygen atoms

3(0.98 - x) + 2x = 2

2.94 - 3x + 2x = 2

x = 2.94 - 2 = 0.94

hence, Number of Ni (III) atoms present = 0.98-.94=0.04

Hence, the fraction of $N{i}^{+2}$ and $N{i}^{+3}$ is 0.94 and 0.04 respectively.