Analysis shows that nickel oxide has the formula `Ni_(0.98)O_(1.00)`. What fractions of nickel "exist" as `Ni^(2+)` and `Ni^(3+)` ions?

Explanation

The ration of Ni and O atoms in pure nickel oxide (NiO) = `1:1`
Let x be the no. of Ni (II) atoms replaced by Ni (III) atoms in the oxide.
`therefore` No. of Ni (II) atoms present = `(0.98-x)`
Since the oxide is neutral in nature,
Charge on Ni atoms = Charge on oxygen atoms
`2(0.98-x)+3x=2`
`1.96-2x+3x=2`
`x=2-1.96=0.04`
`%"of Ni (II) atoms in nickel oxide"=("No. of Ni (III) atoms")/("Total no. of Ni atoms")xx100=(0.04)/(0.98)xx100=4.01%`
`%` of Ni (II) atoms in nickel oxide = `100-4.01=95.99%`