The Solid State Quiz-9
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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: The conductance through electrons is called n-type conduction and if through positive holes it is called p-type conduction.
Statement 2: Doping involves preparation of semiconductors by the presence of impurities in the intrinsic semiconductor.
Statement 2: Doping involves preparation of semiconductors by the presence of impurities in the intrinsic semiconductor.
Solution
(d) Both are facts.
(d) Both are facts.
Q2.Statement 1: Ferromagnetic substances are strongly attracted by magnetic field.
Statement 2: Ferromagnetism arises due to spontaneous alignment magnetic moments of ions or atoms in the same direction. :
Statement 2: Ferromagnetism arises due to spontaneous alignment magnetic moments of ions or atoms in the same direction. :
Solution
(c) Explanation is correct reason for statement.
(c) Explanation is correct reason for statement.
Q3. Statement 1:In any ionic solid [MX] with Schottky defect, the number of positive and negative ions are same
Statement 2:An equal number of cation and anion vacancies is present
Statement 2:An equal number of cation and anion vacancies is present
Solution
(a) Schottky defect arises when equal number of cations and anions are missing from the lattice
(a) Schottky defect arises when equal number of cations and anions are missing from the lattice
Q4. Statement 1:In CsCl crystal, Cs^⊕ ions adopt bcc arrangement
Statement 2:For N atoms adopting bcc arrangement, there are 2N TVs
Solution
(c) (A) is correct but (R) is wrong
Correct(R ): For N atoms adoping fcc arrangement, there are 2N TVs
(c) (A) is correct but (R) is wrong
Correct(R ): For N atoms adoping fcc arrangement, there are 2N TVs
Q5.Statement 1:Diamond and graphite are polymorphic forms.
Statement 2:Carbon adopts different structural arrangements under different conditions to give there two forms.
Statement 2:Carbon adopts different structural arrangements under different conditions to give there two forms.
Solution
(a) Same substance adopt different structural arrangements under different conditions, such arrangements are called polymorphic froms. So, diamond and graphite have same molecular formula but different structure. Diamond is tetrahedral and graphite is hexagonal.
(a) Same substance adopt different structural arrangements under different conditions, such arrangements are called polymorphic froms. So, diamond and graphite have same molecular formula but different structure. Diamond is tetrahedral and graphite is hexagonal.
Q6. Statement 1:Triclinic system is the most unsymmetrical system
Statement 2: No axial angle is equal to 90° in triclinic system
Statement 2: No axial angle is equal to 90° in triclinic system
Solution
(b) Assertion is correct
Correct (R):Axial angles are not equal to each other
(b) Assertion is correct
Correct (R):Axial angles are not equal to each other
Q7.Statement 1: Covalent crystals have higher melting point
Statement 2: Covalent bonds are stronger than ionic bonds
Statement 2: Covalent bonds are stronger than ionic bonds
Solution
(c) Assertion is correct since higher melting points of covalent crystals are due to network structures Correct (R):Covalent bonds are weaker than ionic bonds
(c) Assertion is correct since higher melting points of covalent crystals are due to network structures Correct (R):Covalent bonds are weaker than ionic bonds
Q8.Statement 1: Co-ordination number of CsCl changes from 8 : 8 to 6 : 6 on heating.
Statement 2: The crystal structure of CsCl changes to NaCl on heating.
Statement 2: The crystal structure of CsCl changes to NaCl on heating.
Solution
(c) These are the correct facts.
(c) These are the correct facts.
Q9.Statement 1: Group-15-doped crystals of Si are called n-type semi conductors
Statement 2: Neutrons are responsible for the semi-conducting properties
Statement 2: Neutrons are responsible for the semi-conducting properties
Solution
(c) (A) is correct Correct (R): n stands for negative so electrons are responsible for semiconducting properties
(c) (A) is correct Correct (R): n stands for negative so electrons are responsible for semiconducting properties
Q10.Statement 1: Graphite is an example of tetragonal crystal system.
Statement 2: For a tetragonal system a=b≠c,α=β=90°,y=120°
Statement 2: For a tetragonal system a=b≠c,α=β=90°,y=120°
Solution
(d) Liken quartz and ice, graphite is an example of hexagonal system. For this α=β=90° and γ=120° and a=b≠c For a tetragonal system α=β=γ=90° and a=b≠c
(d) Liken quartz and ice, graphite is an example of hexagonal system. For this α=β=90° and γ=120° and a=b≠c For a tetragonal system α=β=γ=90° and a=b≠c
