Analysis shows nickel oxide has formula Ni0.98 O1.00 what fraction of ni2+ and ni3+ ions in give oxide?

Hello student,

The formula of nickel oxide is Ni 0.98 :1.00.
Therefore, the ratio of the number of Ni atoms to the number of O atoms,

Ni : O = 0.98 : 1.00 = 98 : 100

Now, total charge on 100 O2 -ions = 100 × ( - 2) = - 200

Let the number of Ni2+ions be x.

So, the number of Ni3+ions is 98 - x.

Now, total charge on Ni2+ions = x(+2) = +2x

And, total charge on Ni3+ions = (98 - x)(+3) = 294 - 3x

Since, the compound is neutral, we can write: 2x+ (294 - 3x) + ( - 200) = 0

⇒ - x+ 94 = 0 ⇒ x= 94

Therefore, number of Ni2+ions = 94

And, number of Ni3+ions = 98 - 94 = 4

Hence, fraction of nickel that exists as Ni2+= 94/98 = 0.959

And, fraction of nickel that exists as Ni3+= 4/98 = 0.041

All the Best
Regards
Ravleen Kaur