Chemistry Class 12th Chapter 1 Quiz
14 Questions
7 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the key difference between substitutional impurity defect and interstitial impurity defect?

  • Both substitutional and interstitial defects involve impurity atoms occupying spaces between host atoms.
  • Substitutional defect involves impurity atoms occupying spaces between host atoms, whereas interstitial defect involves impurity atoms replacing host atoms.
  • Substitutional defect involves impurity atoms replacing host atoms, whereas interstitial defect involves impurity atoms occupying spaces between host atoms. (correct)
  • Both substitutional and interstitial defects involve impurity atoms replacing host atoms.
  • What differentiates Schottky defect from Frenkel defect?

  • Schottky defect involves vacancies of both cations and anions, while Frenkel defect involves only cation vacancies. (correct)
  • Schottky defect involves vacancies of both cations and anions, while Frenkel defect involves only anion vacancies.
  • Schottky defect involves only anion vacancies, while Frenkel defect involves both cation and anion vacancies.
  • Schottky defect involves only cation vacancies, while Frenkel defect involves both cation and anion vacancies.
  • Why are ionic solids often hard and brittle?

  • Due to the presence of metal deficiency defects reducing flexibility.
  • Due to low coordination number of atoms in the crystal lattice.
  • Due to the presence of Schottky defects which increase hardness.
  • Due to strong electrostatic forces between oppositely charged ions. (correct)
  • In a face-centered cubic (FCC) structure, how many atoms are present in total?

    <p>8</p> Signup and view all the answers

    What is the coordination number of atoms in a simple cubic crystal lattice?

    <p>4</p> Signup and view all the answers

    Why is it important to classify crystals into distinct types?

    <p>To understand their mechanical behavior.</p> Signup and view all the answers

    What structural feature can be used to differentiate crystalline solids from amorphous solids?

    <p>Presence of long-range order in crystalline solids.</p> Signup and view all the answers

    What type of defect arises when an impurity atom replaces a host atom in a crystal lattice?

    <p>Interstitial impurity defect</p> Signup and view all the answers

    In a crystal lattice, which defect involves the movement of an atom from its original site into an interstitial space?

    <p>Frenkel defect</p> Signup and view all the answers

    Which of the following represents a metal deficiency defect in a crystal lattice?

    <p>Schottky defect</p> Signup and view all the answers

    What is the consequence of Schottky defect in a crystal lattice?

    <p>Decrease in density</p> Signup and view all the answers

    In a compound with hexagonal close-packed structure, how many total voids are formed in 0.4 mol of it?

    <p>$0.4 \times 12$</p> Signup and view all the answers

    Which type of solid is characterized by having a different arrangement in different directions?

    <p>Crystalline solid</p> Signup and view all the answers

    What is the coordination number of atoms in a simple cubic crystal lattice?

    <p>8</p> Signup and view all the answers

    Study Notes

    • The text discusses various topics in the context of 12th grade Chemistry, including impurity defects, types of solids, and crystal lattices.
    • Substitutional impurity defect: A type of impurity where an atom of the impurity replaces a host atom in the crystal lattice.
    • Interstitial impurity defect: A type of impurity where an atom occupies an interstitial site in the crystal lattice between host atoms.
    • Schottky defect: A pair of ions, one cation and one anion, are missing from their lattice sites in an ionic crystal.
    • Frenkel defect: An atom, usually a smaller cation, is displaced from its normal lattice site to an interstitial site, leaving a vacancy behind.
    • Metal deficiency defect: Formed when a metal atom is missing from its normal lattice site and is replaced by a metal ion in an interstitial position.
    • Consequences of Schottky defect: Formation of "depletion regions" resulting in increased resistance and decreased conductivity.
    • A hexagonal close packed (hcp) structure has: i) six octahedral voids per unit cell, ii) twelve tetrahedral voids per unit cell, iii) a total of eighteen voids per unit cell for 0.4 moles.
    • Silver: A noble metal.
    • P4: A tetrahedral molecule consisting of four identical atoms.
    • Diamond: A crystal structure where each carbon atom is tetrahedrally bonded to four neighboring carbon atoms.
    • NaCl: An ionic solid composed of sodium and chloride ions.
    • Anisotropy: A property of crystalline solids where physical properties such as electrical conductivity, magnetic susceptibility, and refractive index vary with direction.
    • Crystalline solids: Solids with an ordered and repeating internal structure, where each particle has a definite position.
    • Amorphous solids: Solids without a long-range order, having a disordered and random structure.
    • Simple cubic crystal lattice: A crystal structure where each atom is surrounded by eight nearest neighbors at the corners of a cube.
    • Coordination number of atoms in simple cubic crystal lattice: Each atom is surrounded by eight nearest neighbors.
    • Diamond, P4, and Brass: i) Diamond is a crystal structure, ii) P4 is a tetrahedral molecule, iii) Brass is an alloy of copper and zinc.
    • Schottky defect in a solid: The formation of a Schottky defect pair causes the creation of "depletion regions" where the charge at the region's edges is neutral, which can result in an increase in resistance and a decrease in conductivity.
    • Relation between radius of an atom and edge length in body-centered cubic crystal: The edge length is given by 2 * r * sqrt(2 + sqrt(2)), where r is the radius of an atom.
    • A face-centered cube (FCC) consists of: i) One atom at each corner, ii) One atom at the center of each face, making a total of 55 atoms per unit cell.
    • Ionic solids: i) Are formed from the strong electrostatic forces between oppositely charged ions, ii) Are hard and brittle due to the strong forces holding the ions in place.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    Test your knowledge on substitutional and interstitial impurity defects, Schottky and Frenkel defects, metal deficiency defects, consequences of Schottky defect, and crystal structures in Chemistry Class 12 Chapter 1.

    Use Quizgecko on...
    Browser
    Browser