11..i think statement 2 is false
1. Statement-1: In diamond carbon atoms occupy alternate tetrahedral voids in the FCC lattice formed by the carbon atoms
Statement-2: In diamond, packing fraction ismore than 74%.
2. Which of the following properties of themetal gets changed due to formation of interstitial carbide.
(A)Density (B)Hardness (C)Malleability (D)Electrical conductivity
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8 Answers
29For the first one..carbon forms a Wurtzrite Structure similar to that of ZnS..so the packing fraction will be greater than 74% ...but the second statement is not a correct explanation of first..so i go with B..
Ans2..i think the answer shud be A,B and C ..
as the carbon atoms occupy the voids so density shud increase..
29In the second question u can take the case of iron and steel...pure iron is soft and steel is hard..so i took this case for options B and C...not sure of the answers...maybe i am right..
1@govind its not wurtizite but zinc blende type
and we can compare both structure due their geometry
in diamond C is tetrahedrally surrounded by other C's so is the case ZnS (blende) it is fcc packing with Zn2+ occupying alternate tetrahedral voids
so i think reason is falsese because packing fraction >74%
1@govind
steel is not a carbide but say cementite Fe3C
@Soumik
WC tungsten carbide is a very hard substance (edited)
WC is an abrasive (editedx2)
so>>>>A,B,C
electrical conductivity remains comparable
29Ya diamond forms ZnS zinc blende structure..but in rare cases forms wutzrite too(dont worry that's an exception)..but why statement 2 is false Tom?
@Tapas..i meant Fe3C only..that's an important component in steel's manufacturing..
1WURTZITE STRUCTURE (Wikipedia)
The wurtzite group includes: Cadmoselite CdSe, Greenockite CdS, Mátraite ZnS and Rambergite MnS, in addition to wurtzite.
Diamond Lattice
