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