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In a crystalline solid,atoms of X from fcc packing and the atoms of Y occupy all octahedral voids.If the atoms along one body diagnal are removed then the simplest formula of the crystalline solid will be:A. XYB. `X_(4)Y_(3)`C. `X_(5)Y_(4)`D. `X_(4)Y_(5)` |
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Answer» Correct Answer - C Number of atoms of X in fcc packing (at corners and face centres of cubic unit cell) `=8xx(1)/(8)+6xx(1)/(2)=4` Number of atoms of Y at octahedral voids =4 Along one body diagonal there are two X atoms atoms and one Y atom. Number of effective atoms of X after removal `=4-2xx(1)/(8)=(15)/(4)` Number of effective atoms of Y after removal `=4-1=3` `X:Y=(15)/(4):3` `=5:4` `therefore` SImplest formula `=X_(5)Y_(4)` |
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