Chemistry

Chemical Bonding and Molecular Structure

1,420 Questions

This section tests your knowledge of chemical bonding, molecular structure, and hybridization. It covers ionic and covalent bonds, octet rule exceptions, and molecular geometry. These chemistry questions are common in various competitive entrance examinations.

Ionic and covalent bondsHybridisation of elementsOctet rule exceptionsMolecular geometryIntermolecular forces

Chemical Bonding and Molecular Structure Questions

Multiple choice

Which of the following statements is incorrect about electrolytes such as HCl, H2SO4 and HNO3?

  1. These allow a large amount of electricity to flow through them.

  2. These are poor conductors of electricity.

  3. These are almost completely dissociated in fused or aqueous state.

  4. Their solutions contain almost only free mobile ions.

  5. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The given substances are examples of strong electrolytes and strong electrolytes are good conductors of electricity.

Multiple choice

In which of the following spectroscopy techniques does the transition occur between magnetic energy levels of paired electrons in a molecule?

  1. Electron spin resonance spectroscopy

  2. Nuclear Magnetic Resonance spectroscopy

  3. Raman spectroscopy

  4. Infrared spectroscopy

  5. Visible spectroscopy
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This answer is correct as in electron spin resonance the transition occurs between magnetic energy levels of paired electrons and region of EM spectrum is microwave. It involves the detection of physical phenomenon of absorption of electromagnetic radiation in microwave region by paramagnetic species.

Multiple choice

Which of the following statements is true regarding different types of energies associated with a molecule?

  1. The molecule possesses vibrational energy which is associated with transitions of an electron from ground energy level to excited state level.

  2. When the centre of gravity does not change during to and fro motion of nuclei of the molecule, the molecule is said to posses translational energy.

  3. During the motion if the centre of gravity of the molecule changes the molecule which possesses vibrational energy.

  4. Considering an axis perpendicular to the internuclear axis and passing through the centre of gravity of the molecule, then the molecule needs electronic energy to rotate about this axis.

  5. Electronic Energy > Vibrational Energy > Rotational Energy > Translational Energy
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This answer is correct as electronic energy is greater than vibrational energy, which is greater than rotational energy, whihc is greater than translational energy. Thus, the total energy is given by: Etotal = Eelec + Evib + Erot + Etrans

Multiple choice

Which of the following sets represents bidentate ligands only?

  1. en, C2O42-, acac, dmpe

  2. EDTA, dmpe, SCN‑, NO2-

  3. dien, acac, dmpe, C2O42-

  4. EDTA, en, acac, SCN‑

  5. C2O42-, acac, dien, NO2-
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ethylenediammine (en): Bidentate ligand Oxalate ion (C2O42-): Bidentate ligand Acetylacetonate ion (acac): Bidentate ligand Dimethylphosphinomethane (dmpe): Bidentate ligand

Multiple choice

Water molecules consist of two covalent bonds between 1 oxygen atom and 2 hydrogen atoms, i.e. H-O-H. Therefore, according to symmetry principles, it should be a linear structure but instead it has

  1. elongated linear structure that results into the hydrogen bonding

  2. bent structure owing to lone pairs on oxygen

  3. curved V-shaped structure with lone pairs on both sides of oxygen

  4. flexible structure that can attain different shapes under different circumstances
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The water molecule should be symmetrical and therefore, linear. But the repulsion between the two lone pairs of oxygen and further the lone pair-bond pair repulsion cause it to distort to a bent-shaped structure with lone pairs being on one side and bond pairs on the other.

Multiple choice

Which of the following statements is/are true for carbon?

(a) Carbon can form only four single covalent bonds. (b) It can form single, double and triple bonds. (c) To complete its octet, carbon has to form three bonds. (d) To complete its octet, carbon has to form four bonds.

  1. Only (a) and (c)

  2. Only (b) and (d)

  3. Only (b)

  4. Only (d)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Carbon can form single, double and triple bonds and to complete its octet, it has to form four bonds due to its tetravalency.