The Solid State Quiz-11
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IIT JEE exam which consists of JEE Main and JEE Advanced is one of the most important entrance exams for engineering aspirants. The exam is held for candidates who are aspiring to pursue a career in the field of engineering and technical studies.
Chemistry is important because everything you do is chemistry! Even your body is made of chemicals. Chemical reactions occur when you breathe, eat, or just sit there reading. All matter is made of chemicals, so the importance of chemistry is that it's the study of everything..
Q1.Statement 1: Band gap in germanium is small.
Statement 2: The energy spread of each germanium atomic energy level is infinitesimally small.
Solution
(a) Follow text.
(a) Follow text.
Q2.Statement 1: Bragg’s equation has no solution if n=2 and λ=d.
Statement 2: Bragg’s equation is : nλ=2d sinθ
:
Solution
(c) If n=2 and λ>d then sin θ > 1 which is not possible.
(c) If n=2 and λ>d then sin θ > 1 which is not possible.
Q3. Statement 1: 6 : 6 co-ordination at normal temperature and pressure changes to 8 : 8 co-ordinations at high pressure.
Statement 2: Pressure influences the structure of solids.
Solution
(c) Explanation is correct reason for statement.
(c) Explanation is correct reason for statement.
Q4. Statement 1: Solids having more F-centres possess intense colours. Statement 2: Excess of Na^+ in NaCl solid having F-centres makes it appear to pink.
Solution
(a) Excess of Na^+ in NaCl solid at F-centres develops yellow colour.
(a) Excess of Na^+ in NaCl solid at F-centres develops yellow colour.
Q5.Statement 1: The size of a cation is larger in TV than in OV
Statement 2: Cations occupy more space than anions is crystal packing
Solution
(c) Correct (A): OV is larger in size than TV Correct (R):Cations are generally smaller. They occupy voids instead of lattice points and hence occupy less space
(c) Correct (A): OV is larger in size than TV Correct (R):Cations are generally smaller. They occupy voids instead of lattice points and hence occupy less space
Q6. Statement 1: The close packing of atoms in cubic structure is in the order, fcc > bcc > sc.
Statement 2: Packing density = (volumes of unit cell)/a^3
Solution
(c) Explanation is correct reason for statement.
(c) Explanation is correct reason for statement.
Q7.Statement 1: Zinc blende and wurtzite both have fcc arrangement of S^(2-) ions
Statement 2: A unit cell of both has four formula units of ZnS
Solution
(c) Correct (A):Zinc blende has fcc arrangement of S^(2-)ions while wurtzite has hcp arrangement of S^(2-) ions Correct (R):A unit cell of zinc blende has 4 formula units while that of wurtzite has 6 formula units of ZnS
(c) Correct (A):Zinc blende has fcc arrangement of S^(2-)ions while wurtzite has hcp arrangement of S^(2-) ions Correct (R):A unit cell of zinc blende has 4 formula units while that of wurtzite has 6 formula units of ZnS
Q8.Statement 1: Non-stoichiometric compounds are called Bertholide compounds. NaCl and KCl crystal, when heated in an atmosphere of Na and K vapours, respectively, they impart violet and yellow colours to NaCl and KCl, respectively
Statement 2: Metal excess defect is due to the presence of extra cations at the interstitial sites. The excess metal ions move to the interstitial sites and the electrons to the neighbouring sites. The colour results by the excitation of these electrons by absorbing suitable energy from visible light. When the excited electron comes back to the ground state, there is emission of radiation in the visible region and gives complimentary colour
Solution
(d) Correct (A): NaCl and KCl impart yellow and violet colour, respectively (R) is correct but not correct explanation of (A)
(d) Correct (A): NaCl and KCl impart yellow and violet colour, respectively (R) is correct but not correct explanation of (A)
Q9.Statement 1: hcp is more closely packed than ccp
Statement 2: hcp has a CN of 12, whereas ccp has a CN of 8
Solution
(c) Correct (A):hcp and ccp are equally closest packed since space occupied in both = 74% Correct (R):Both have CN=12
(c) Correct (A):hcp and ccp are equally closest packed since space occupied in both = 74% Correct (R):Both have CN=12
Q10.Statement 1: Solids containing F-centres are paramagnetic.
Statement 2: F-centres solids possess holes occupied by unpaired electrons.
Solution
(c) Explanation is correct reason for statement.
(c) Explanation is correct reason for statement.
