1is the ans XY2O4?
In a cubic closed packed structure of mixed oxides,the lattice is made pup of oxide ions,20%of tetrahedral voids are occupied by divalent x+2 ions an 50% of the octahedral voids are occupied by trivalent Y+3 ions. The formula of the oxide is .....
a)X2YO4
b)X4Y5O10
c)X5Y4O10
d)XY2O4
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3 Answers
29In Cubic Closed Packing..the number of oxides atom in a unit cell = 4
Number of octahedral voids = 4
Number of tetrahedral voids = 8
Since 50% of octahedral voids are occupied so number of atoms of Y3+ in one unit cell = 2
Since 20% of the octahedral voids are occupied so number of X2+ in one unit cell = 20/100 * 8 = 8/5
So the formula is X8/5Y2O4
so the formula becomes X4Y5O10
According to this answer shud be B (Actual way of doing questions like this)
Another way of doing such questions : the lattice is always electrically neutral..according to that the answer shud be D (objective way of doing questions )
Both the abv methods seem to be correct but they are contradicting..
I guess this question came in the Science Oylmpiad organised by Science Olympiad Foundation(S.O.F)
It seems like there is some problem in the question..
