Chemistry

Chemical Bonding and Molecular Structure

1,277 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 sets of molecular ions, have T-shaped geometry?

  1. H3O+, AlCl3 and NO2-

  2. ICl2-, I3- and ClF2-

  3. NF3, PCl3 and SO3

  4. NH2-, BCl3 and ICl2+

  5. BrF3, IF3 and XeOF2
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This option is correct because for minimum repulsion between the electron pairs two lone pairs occupy the basal positions and out of three bond pairs, one occupies basal position and two along axial positions. Thus according to VSEPR theory all molecules, IF3, XeOF2 and BrF3 possess T-shaped geometry.

Multiple choice

Match the Column I molecules/molecular ions with Column II bond orders and Column III magnetic properties:

   
Molecular ion
Bond order
Magnetic character
(i) H2+ a. 2.5 x. Paramagnetic
(ii) C2 b. 3.0 y. Diamagnetic
(iii) CN- c. 0.5
(iv) O2- d. 1.0
(v) NO e. 2.0
(vi) F2 f. 1.5

  1. i - a - y, ii - d - x, iii - b - x, iv - c - y, v - f - x, vi - e - y

  2. i - e - y, ii - c - x, iii - f - x, iv - b - y, v - a - x, vi - d - y

  3. i - c - y, ii - e - x, iii - b - x, iv - f - y, v - a - y, vi - d - x

  4. i - a - x, ii - d - y, iii - b - y, iv - c - x, v - f - y, vi - e - x

  5. i - c - x, ii - e - y, iii - b - y, iv - f - x, v - a - x, vi - d - y
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This option is correct because all the molecular ions are correctly matched with their bond order and magnetic properties. According to molecular orbital energy level diagram: for example of energy levels of molecular orbitals of O2- : σ1s2, σ*1s2, σ2s2, σ*2s2, σ2pz2, π2p x 2=π2py2, π*2px2=π*2py1 Bond order = 1/2 (number of bonding electrons-number of antibonding electrons) = 1/2 (10-7) = 1.5 And due to the presence unpaired electron in π*2py1 molecular orbital, this molecule is paramagnetic.

Multiple choice

Which of the following set is hypervalent molecule?

  1. I3-, XeO4 and SF4

  2. BF3, AlCl3 and ICl2-

  3. XeF2, KrF2 and AlCl3

  4. PCl5, SF6 and SF4+2

  5. XeOF2, XeO3 and I3+
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This option is correct because all molecules exceed the octet rule, and hence all are hypervalent molecules.