TestUstad

All Free Chemistry MCQs with Answers

Every Chemistry question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.

13,720 questions · page 495 of 686

9881. Brittleness of ionic solids is due to the fact that ions arrange themselves in a way to _ each other.

  • A. Attract
  • B. Compress
  • C. Repel
  • D. Overlap

Explanation: To an ionic compound when a force is applied, like charges in the lattice come together due to the force applied and repel each other…

Read the full explanation →
Correct answer: Repel

9882. CI-Cl Bond distance is 5.63 A, while the NaCl bond distance is

  • A. Half of 5.63
  • B. Double to 5.63
  • C. 5.63
  • D. None of these

Explanation: Option A is correct since, in a chlorine molecule, chlorine exists as atoms.

Read the full explanation →
Correct answer: Half of 5.63

9883. Cesium in cesium chloride has the coordination number:

  • A. 6
  • B. 8
  • C. 4
  • D. 5

Explanation: Cesium in cesium chloride has the coordination number 8.

Read the full explanation →
Correct answer: 8

9884. In crystal structure of NaCl, the arrangement of Cl- ions is:

  • A. Face centered cubic
  • B. Body centered cubic
  • C. Simple Cubic
  • D. Hexagonal

Explanation: Option A is correct.The arrangement of Cl- ions in the crystal structure of NaCl is face centered cubic.

Read the full explanation →
Correct answer: Face centered cubic

9885. The number of Cl- ions per unit cell of a simple cubic lattice at the corner is/are:

  • A. 1
  • B. 3
  • C. 4
  • D. 6

Explanation: - In a simple cubic lattice, each corner is shared by eight adjacent unit cells.- Each corner atom/ion contributes (1/8) to the unit cell…

Read the full explanation →
Correct answer: 1

9886. Antifluorite structure is derived from fluorite structure by:

  • A. Heating fluorite crystal lattice
  • B. Subjecting fluorite structure to high pressure
  • C. Interchanging the positions of positive and negative ions in the lattice
  • D. Introducing the impurities to the lattice

Explanation: Since the CN of Fluorite and Antifluorite structure are same, hence by interchanging the positions of cation and anions lattice can be…

Read the full explanation →
Correct answer: Interchanging the positions of positive and negative ions in the lattice

9887. A solid AB2 has fluorite type structure (CaF2). If all the atoms along one of the tetrad axes is removed, then formula of the solid will be:

  • A. A2B5
  • B. A3B8
  • C. A3B5
  • D. A5B8

Explanation: Following is the solution of this problem:

Read the full explanation →
Correct answer: A3B8

9888. If the distance between Na+ and Cl- ions in NaCl crystal is 265 pm, then edge length of the unit cell will be:

  • A. 265 pm
  • B. 530 pm
  • C. 795 pm
  • D. 132.5 pm

Explanation: As we know, Edge length = 2 x distance between Na+ & Cl- Edge length = 2 x 265 = 530 pm Hence, option B is correct.

Read the full explanation →
Correct answer: 530 pm

9889. X+Y- crystallizes in a bcc lattice in which the radius of X+ is 0.4 Å. If all the X+ ions are removed and another cation Z+ is inserted, what should be the maximum radius of the cation Z+ to crystallize in a fcc lattice with Y?

  • A. 0.548 Å
  • B. 0.010 Å
  • C. 0.400 Å
  • D. 0.226 Å

Explanation: Following is the solution of this question:

Read the full explanation →
Correct answer: 0.226 Å

9890. NH4Cl crystallizes in a body-centred cubic lattice with edge length of unit cell equal to 387 pm. If the radius of the Cl− ion is 181 pm, radius of NH4+ ion is:

  • A. 154.1 pm
  • B. 92.6 pm
  • C. 366.3 pm
  • D. None of these

Explanation: In body centred cubic lattice, oppositely charged ions touch each other along the cube.

Read the full explanation →
Correct answer: 154.1 pm

9891. Edge length M+X- (fcc structure) is 7.2 Å. Assuming M+ and X− contact along the cell edge, radius of X− ion is: (rM+=1.6 Å)

  • A. 2.0 Å
  • B. 5.6 Å
  • C. 2.8 Å
  • D. 3.8 Å

Explanation: Following is the solution of this problem:

Read the full explanation →
Correct answer: 2.0 Å

9892. The coordination number of each ion in NaCl is:

  • A. 4
  • B. 8
  • C. 6
  • D. 10

Explanation: In NaCl, each Na+ ion surrounded by six Cl- ions and each Cl- ion is surrounded by six Na+ ions.

Read the full explanation →
Correct answer: 6

9893. Predict the shape of CsCl having a radius ratio of 0.93:

  • A. Tetrahedral
  • B. Octahedral
  • C. Body-centered cubic
  • D. Hexagonal

Explanation: CsCl adopts a body-centered cubic (bcc) arrangement where each Cs⁺ ion is surrounded by 8 Cl⁻ ions and vice versa, giving a coordination…

Read the full explanation →
Correct answer: Body-centered cubic

9894. The shape of P orbital is:

  • A. Dumbbell
  • B. Spherical
  • C. Trigonal
  • D. None of the above

Explanation: The P orbital's dumbbell shape arises from its electron density distribution, with two lobes positioned along an axis and a node at the…

Read the full explanation →
Correct answer: Dumbbell

9895. A crystal system having all sides (a, b and c) unequal and angles α = β = γ = 90 is:

  • A. Cubic
  • B. Rhombohedral
  • C. Orthorhombic
  • D. Hexagonal

Explanation: This is correct because an orthorhombic system has all three sides unequal (a ≠ b ≠ c), but all angles are 90° (α = β = γ = 90°).

Read the full explanation →
Correct answer: Orthorhombic

9896. A solid AB2 has a fluorite-type structure (CaF2). If all the atoms along one of the tetrad axes are removed, then the formula of the solid will be:

  • A. A2B5
  • B. A3B8
  • C. A3B5
  • D. A5B8

Explanation: Following is the solution of this problem:

Read the full explanation →
Correct answer: A3B8

9897. If the distance between Na+ and Cl- ions in NaCl crystal is 265 pm, then the edge length of the unit cell will be:

  • A. 265 pm
  • B. 530 pm
  • C. 795 pm
  • D. 132.5 pm

Explanation: In the face-centered cubic (FCC). structure of NaCl, the edge length (a) of the unit cell is twice the distance between adjacent ions.

Read the full explanation →
Correct answer: 530 pm

9898. An element 'A' has a face-centred cubic structure with edge length equal to 361 pm. The apparent radius of atom 'A' is :

  • A. 127.6 pm
  • B. 180.5 pm
  • C. 160.5 pm
  • D. 64 pm

Explanation: Following is the solution to this problem:

Read the full explanation →
Correct answer: 127.6 pm

9899. An element X (Atomic weight = 80 g/mol) has a face-centered cubic structure. Calculate the number of unit cells in 8 g of X:

  • A. 0.4 x NA
  • B. 0.1 x NA
  • C. 4 x NA
  • D. 0.025 x NA

Explanation: First, find the moles of X: 8 g / 80 g/mol = 0.1 mol. Find the number of atoms: 0.1 × Nₐ. An FCC unit cell contains 4 atoms.

Read the full explanation →
Correct answer: 0.025 x NA

9900. Which of the following statements (s) is/are correct? A. Ferromagnetic substances are permanently magnetised.B. AgBr shows both Schottky and Frenkel defects.C. One tetrahedral void per atom is present in the HCP structure.

  • A. A & C
  • B. A, B & C
  • C. B only
  • D. A & B

Explanation: A.Ferromagnetic substances are permanently magnetised.Correct.Ferromagnetic materials (like iron, cobalt, nickel) have magnetic domains…

Read the full explanation →
Correct answer: A & B
Start Free Chemistry Practice MCQs Test