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 contains a co-ordinate covalent bond?

  1. HCl

  2. BaCl2<o:p></o:p>

  3. N2H5+<o:p></o:p>

  4. H2O<o:p></o:p>
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Co-ordinate covalent bond is formed by sharing one pair of electrons between the two atoms. In this pair, both electrons come from one atom and the remaining atom donates none. For this, one of the atoms should have at least one lone pair of electrons. The other atom should have an empty valance orbital.

Multiple choice

Which of the following has zero bond order?

  1. N2

  2. O2

  3. F2

  4. Ne2
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Bond order = (Nb-Na)/2 Where, Nb = number of electrons in bonding orbitals Na = number of electrons in antibonding orbitals Ne2 has equal number of bonding and antibonding electrons. Hence, bond order of Ne2 is zero.

Multiple choice

Which of the following does not has a linear arrangement of atom?

  1. CO2

  2. C2H2

  3. BeH2

  4. H2O
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The oxygen has 6 valence electrons and thus needs 2 more electrons from 2 hydrogen atoms to complete its octet. Then, this leaves two lone electron pairs that are not bonded to any other atom. The two hydrogen atoms and the two lone electron pairs are as far apart as possible at nearly 109o bond angle. This is tetrahedral electron pair geometry. The two lone electron pairs exert a little extra repulsion on the two bonding hydrogen atoms to create a slight compression to a 104o bond angle. The water molecule is in bent molecular geometry because of the lone pairs of electrons.

Multiple choice

Which of the following bond(s) is/are present in ammonium chloride?

  1. Only ionic

  2. Only covalent

  3. Covalent and ionic

  4. Ionic, covalent and co-ordinate
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

There is no covalent interaction between ammonium and chloride ions in the solid state. The ions are arranged in a cesium chloride structure having large cations and smaller anions in the ratio 1:1. However, bonding between nitrogen and the four hydrogens within the ammonium ion itself is covalent. 

Multiple choice

Which of the following has the strongest bond?

  1. C-C

  2. C=C

  3. C≡C

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Triple bond on the other hand adds another pi orbital to the existing sigma and pi orbitals making the triple bond stronger than the previous two and also shorter. The order of strength of bonds is C≡C > C=C > C-C.

Multiple choice

Which of the following is not a planar molecule?

  1. BCl3

  2. C2H4

  3. XeF<sub style="color:">4

  4. PCl<sub style="color:">3
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

PCl3 has sp3 hybridisation. Due to the presence of three bonding pairs and one lone pair, the resulting geometry is pyramidal.