11Ans 4) (a) , (b) , (c) ??????????
:: Single option Correct ::
1) A metallic element crystallises into a lattice containing a sequnece of layers of ABABAB..
Any packing of spheres leaves out voids in the lattice.
Percentage of Empty Space (by Volume) is -
a)52% b)48% c)50% d)74%
2)Consider the foll. statements-
I- If an Fe2+ is missing frm its lattice site in FeO, there must be 2 Fe3+ somewhere in the lattice to balance electrical charges.
II- Crystals with metal deficiency defects are called Super-Conductors.
III- Crystals with metal deficiency defects are called SEmiconductors.
Correct Statements are-
a) I, II b) I, III c) II only d) I only
:: Multi Answer ::
3) FCC type structure is for-
a) CsCl b) AgCl c) MgO d) KCl
4) Glasses & plastics are-
a) Amorphous solids
b) Supercooled Liquids
c) Isotropic
d) Ferromagnetic
-
UP 0 DOWN 0 0 15
15 Answers
135) Also, How is the coordination no. in a particular lattice Increased/Decreased,,, matlab in terms of Increasing/Decreasing Pressure & Temperature...?
11Ans 5) http://www.targetiit.com/iit-jee-forum/posts/solid-doubt-s-again-13413.html
13Yes, so (c) ought to be correct.
These days am mostly bumping into Qn(s) with wrong answers,,,Mysteriously..!! :D
13Answers (tht are given; not necessarily correct) -
1)- b...!!
2)- Again b..!!
3)- b and c
4)- a and b
13Maine aisa kab kahaa ...?!?!
Waise, i think all the answers given in the book are WRong.
1definitely glass is isotropic
for 1) packing is 52% hence empty space is 48%
so b
for 2) in many cases
Metal deficiency defect is due to missing of a cation of lower valency and presence of a cation of higher valency
which forms semiconductors..eg silicon doped wit p
for 3) CsCl gives simple cubic because of large cation....
FCC by small cations only like in KCl, MgO, n AgCl
so ans must be b,c,d
for 4) a,b,c
