question_answer 40)

Analysis shows that nickel oxide has formula . What fractions of nickel exist as Ni2+ and Ni3+ ions?  

Answer:

Formula of nickel oxide :   or Ni98 O100 Let no. of Ni2+  ions = x  no. of Ni3+ ions = 98 - x Total - ve charge on 100, O-? ion = 200 Total + ve charge x, Ni2+ ions = 2x Total + ve charge on (98 - x), Ni3+ ions = 3 (98 - x)             Total + vc charge on Ni ions = 2x + 3(98 - x) For the substance to be electrically neutral Total +ve charge = Total ?ve charge 2x + 3(98 - x) = 200 2x - 3x = 200 ? 294 x = 94 Percentage of Ni2+ ions  Percentage of  ions = 100?96 = 4%