If NaCl is doped with 10–3 mol % of SrClwhat is the concentration of cation vacancies?
6.02 x 10 23
6.02 x 10 20
6.02 x 10 18
6.02 x 10 19
Q.2.
A cubic solid is made of two elements P and Q. Atoms of Q are at the corners of the cube and P at the body-centre. What is the formula of the compound?
PQ
P2Q
PQ2
PQ4
Q.3.
The total number of tetrahedral voids and octahedral voids per unit cell of face-centred cell (fcc) are
8, 4
4, 8
2, 4
4, 2
Q.4.
Niobium crystallises in body-centred cubic structure. If density is 8.g cm–calculate atomic radius of niobium using its atomic massu.
331 pm
143 pm
331 nm
143 nm
Q.5.
Iron oxide crystallises in a hexagonal close-packed array of oxide ions with two out of every three octahedral holes occupied by iron ions. What is the formula of the iron oxide?
FeO
Fe2O3
Fe3O4
None of these
Q.6.
On doping Ge metal with a little of In(Indium) we get
n - type semiconductor
p-type semiconductor
insulator
rectifier
Q.7.
When electrons are trapped in the crystal in the anionic vacancy, the defect is known as
Schottky defect
Frenkel defect
Stoichiometric defect
F-centre
Q.8.
Schottky defect is observed when
unequal number of cations and anions is missing from the crystal lattice.
equal number of cations and anions is missing from the crystal lattice.
an ion leaves its normal site and occupy interstitial site.
density of the crystal increases.
Q.9.
Inclose packing the ABCABCABC.....pattern gives rise to which type of close packing?
Hexagonal Close Packing (hcp)
Cubic Close Packing (ccp)
Face Centred Cubic Packing (fcc)
Both ccp and fcc
Q.10.
The number of atoms per unit cell in simple, fcc and bcc unit cells are
1, 4, 2
1, 2, 4
2, 1, 4
2, 4, 1
Support mcqgeeks.com by disabling your adblocker.
Please disable the adBlock and continue. Thank you.