Solid

13 free MDCAT Chemistry MCQs on Solid (PM&DC syllabus), each with the answer, an explanation and the textbook line it comes from. Tap to check, no sign-up.

Tap an answer to check it · 13 questions

1. Question 1

   The external shape in which a crystal usually grows in its natural state is called its:
   • ACleavage
   • BHabit
   • CSymmetry
   • DAnisotropy
   Show answer and explanation

   Answer: B) Habit

   Sodium chloride, for example, has a cubic habit. Source: Chemistry 11 KPK (taleem360.com), p. 192.

2. Question 2

   The energy released when one mole of an ionic crystal is formed from gaseous ions of opposite charge is:
   • AElectron affinity
   • BIonization energy
   • CLattice energy
   • DHeat of fusion
   Show answer and explanation

   Answer: C) Lattice energy

   Lattice energy of NaCl is -787 kJ/mol; it is found indirectly by a Born-Haber cycle. Source: Chemistry 11 KPK (taleem360.com), p. 203.

3. Question 3

   On crystallization, sodium chloride forms a:
   • AFace centered cubic lattice
   • BBody centered cubic lattice
   • CSimple cubic lattice
   • DHexagonal lattice
   Show answer and explanation

   Answer: A) Face centered cubic lattice

   In the fcc NaCl lattice each Na+ is surrounded by six Cl- ions and vice versa. Source: Chemistry 11 KPK (taleem360.com), p. 200.

4. Question 4

   Unlike crystalline solids, amorphous solids:
   • AShow anisotropy
   • BMelt sharply
   • CMelt over a range
   • DBreak at cleavage planes
   Show answer and explanation

   Answer: C) Melt over a range

   The other three are properties of crystalline solids. Source: Chemistry 11 KPK (taleem360.com), p. 196.

5. Question 5

   According to kinetic molecular theory, particles of a solid possess:
   • AAll three kinds of kinetic energy
   • BOnly translational kinetic energy
   • COnly rotational kinetic energy
   • DOnly vibrational kinetic energy
   Show answer and explanation

   Answer: D) Only vibrational kinetic energy

   Particles are fixed and can only vibrate about their mean positions. Source: Chemistry 11 KPK (taleem360.com), p. 188.

6. Question 6

   An ionic crystal with radius ratio between 0.414 and 0.732 has coordination number and structure:
   • A4, tetrahedral
   • B6, octahedral
   • C8, cubic
   • D3, trigonal planar
   Show answer and explanation

   Answer: B) 6, octahedral

   NaCl (0.54) and MgO fall here; CsCl (0.732-1) has coordination number 8. Source: Chemistry 11 KPK (taleem360.com), p. 202.

7. Question 7

   Lattice energy of an ionic compound increases with:
   • AIncrease in charge and size
   • BDecrease in charge, increase in size
   • CIncrease in charge, decrease in size
   • DDecrease in charge and size
   Show answer and explanation

   Answer: C) Increase in charge, decrease in size

   Smaller, more highly charged ions attract more strongly (NaF 895 > NaCl 787 > NaI 690 kJ/mol). Source: Chemistry 11 KPK (taleem360.com), p. 203.

8. Question 8

   Which of these has the highest lattice energy?
   • AKI
   • BNaCl
   • CNaI
   • DNaF
   Show answer and explanation

   Answer: D) NaF

   F- is the smallest anion: NaF 895, NaCl 787, NaI 690, KI 630 kJ/mol. Source: Chemistry 11 KPK (taleem360.com), p. 203.

9. Question 9

   Ionic solids conduct electricity:
   • AWhen melted or dissolved
   • BIn the solid state
   • CIn no state at all
   • DOnly when cooled
   Show answer and explanation

   Answer: A) When melted or dissolved

   In the solid the ions only vibrate in fixed positions; melting or dissolving lets them move. Source: Chemistry 11 KPK (taleem360.com), p. 206.

10. Question 10

    Among covalent solids, the one that conducts electricity is:
    • ADiamond
    • BGraphite
    • CSilicon carbide
    • DQuartz
    Show answer and explanation

    Answer: B) Graphite

    Graphite has mobile electrons between its layers. Source: Chemistry 11 KPK (taleem360.com), p. 207.

11. Question 11

    In ice, each oxygen atom is surrounded tetrahedrally by:
    • ASix H atoms
    • BTwo H atoms
    • CFour H atoms
    • DThree H atoms
    Show answer and explanation

    Answer: C) Four H atoms

    Two H by covalent bonds and two by hydrogen bonds, giving an open structure. Source: Chemistry 11 KPK (taleem360.com), p. 204.

12. Question 12

    Wood and cork seem compressible because under pressure:
    • APores are compressed
    • BMatter itself shrinks
    • CMolecules break apart
    • DBonds become shorter
    Show answer and explanation

    Answer: A) Pores are compressed

    For practical purposes solids are incompressible; only the air-filled pores close. Source: Chemistry 11 KPK (taleem360.com), p. 187.

13. Question 13

    When NaCl is crystallized from a solution containing 10% urea as impurity, its crystals are:
    • ACubic
    • BNeedle like
    • COctahedral
    • DFlat plates
    Show answer and explanation

    Answer: B) Needle like

    Impurities make faces grow at different rates; pure supersaturated solution gives cubes. Source: Chemistry 11 KPK (taleem360.com), p. 192.

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