Analysis shows that nickel oxide has the formula Ni0.98O1.00. What fractions of nickel exist as Ni2+ and Ni3+ ions?

Given formula of nickel oxide = Ni0.98O1.00

Therefore, Ni:O = 0.98:1.00


Total charge on O-2 ion = 100 × (-2) = -200


Now, let the number of Ni2+ ions = x


Therefore, number of Ni+3 = 98- x


Now, since compound is neutral


Therefore, no. of Ni2+ ions + no. of Ni3+ ions +no. of O-2 ions = 0


x (-2) + (98 - x) × (-3) + (-200) = 0


-2x – 294 +3x – 200 =0


x-94 = 0


x = 94


Therefore, the number of Ni2+ ions = 94


Number of ni3+ ions = 98- 94 = 4


Now, fraction of nickel exists as Ni2+ = 0.959


Fraction of nickel exists as Ni 3+ ions = 0.041


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