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

Match the molecules/ions in Group - I with corresponding geometry given in Group - II.

 
Group - I
Group - II
A. ReF8- 1. trigonal prismatic
B. W(CH3)6 2. square antiprismatic
C. Na[CoCl2(NH3)4] 3. distorted trigonal bipyramidal
D. SeF4 4. Octahedral

  1. A - 2, B - 1, C - 4, D - 3

  2. A - 2, B - 4, C - 1, D - 3

  3. A - 1, B - 2, C - 4, D - 3

  4. A - 4, B - 1, C - 2, D - 3

  5. A - 4, B - 2, C - 1, D - 3
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

ReF8- has square antiprismatic molecular geometry (the shape of compounds where eight atoms, groups of atoms, or ligands are arranged around a central atom, defining the vertices of a square antiprism). W(CH3)6 has trigonal prismatic geometry (the shape of compounds where six atoms, groups of atoms, or ligands are arranged around a central atom, defining the vertices of a triangular prism). Na[CoCl2(NH3)4] has octahedral geometry. SeF4 has one lone pair of electrons with distorted trigonal bipyramidal shape. Hence, the representation of codes A - 2, B - 1, C - 4, D - 3 is correct.

Multiple choice

Which of the following statements is/are false? P. The central atom in POCl3 has sp3 hybridisation tetrahedral geometry. Q. The number of F-Br-F bond angle equal to 90 degrees in BrF5 is one. R. XeF5+ and ICl4- have identical hybridisation, but do not have similar shape.

  1. Only P.

  2. Only Q.

  3. Only R.

  4. Only P and Q.

  5. Only Q and R.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

 Based on VSEPR theory BrF5 has one lone pair of electrons and sp3d2 hybridisation with square pyramidal geometry. The bond angle in F-Br-F is 84.8 degrees.    Hence, statement Q is false.

Multiple choice

Which of the following ions have identical geometry? (i) NH4+, (ii) IF4+, (iii) ClO2-, (iv) ClO4

  1. Only i and ii.

  2. ii and iii.

  3. Only i and iv

  4. Only i, ii and iii.

  5. Only ii, iii and iv.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

NH4+ and ClO4- both ions have four bond pairs of electrons and zero lone pairs of electrons with tetrahedral geometry. IF4+ has four bond pairs of electrons and one lone pair of electrons with seasaw geometry. ClO2- has three bond pairs of electrons and two lone pairs of electrons with V-shaped geometry. Hence, i and iv are identical in geometry.

Multiple choice

Which of the following statements is/are false? (P) SeO32- has pyramidal geometry. (Q) Cl2O molecule has two lone pairs of electrons and bent shape. (R) XeF2 and [I(CN)2]- have sp3d and three lone pairs of electrons with linear and bent geometry.

  1. Only P

  2. Only Q

  3. Only R

  4. Only P and Q

  5. Only Q and R
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Both XeF2 and [I(CN)2]- have sp3d and three lone pairs of electrons with linear geometry. Hence, statement R is false.

Multiple choice

Which of the following molecules bears one lone pair and possesses bent shape?

  1. CCl2

  2. OF2

  3. H2O

  4. HgCl2

  5. O3
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The molecules having two bond pairs and one lone pairs of electrons with bent shape are- O3, SO2, CCl2, etc. The molecules having two bond pairs and two lone pairs of electrons with bent shape are- H2O, OF2, etc. The molecules having two bond pairs and zero lone pairs of electrons with linear shape are- BeCl2, HgCl2, CO2, etc.

Multiple choice

Which of the following statements is/are incorrect? (P) I3- is linear shaped and XeCl2 possesses V-shaped geometry. (Q) BF3 and SO3 have same number of bond pairs and lone pairs with identical geometry. (R) XeOF4 molecule has square pyramidal shape.

  1. Only P.

  2. Only Q.

  3. Only R.

  4. Only P and Q.

  5. Only Q and R.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

(P) The molecules/ions having two bond pairs and three lone pairs with linear geometry are- XeF2, I3-, XeCl2, etc. (Q) BF3 and SO3 have three bond pairs and zero lone pairs with identical geometry, trigonal planar. (R) XeOF4 molecule has 5 bond pairs and one lone pair with square pyramidal shape. Hence, statement P is only incorrect.

Multiple choice

Match the Group - I with Group - II.

 
Group - I (molecules/ions) Group - II (corresponding geometry)
A. BH2+ 1. V-shaped
B. SnBr2 2. linear
C. XeF3+ 3. square pyramidal
D. IF5 4. T-shaped

  1. A - 2, B - 1, C - 4, D - 3

  2. A - 2, B - 4, C - 1, D - 3

  3. A - 2, B - 3, C - 1, D - 4

  4. A - 4, B - 1, C - 3, D - 2

  5. A - 2, B - 1, C - 3, D - 4
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

BH2+ has sp hybridisation and zero number of lone pair of electrons with linear shape. SnBr2 has sp2 hybridisation and one lone pair of electrons with V-shaped geometry. XeF3+ has sp3d hybridisation and two lone pair of electrons with T-shaped geometry. IF5 has sp3d2 hybridisation and one lone pair of electrons with square pyramidal geometry. Hence, the representation of codes A - 2, B - 1, C - 4, D - 3 is correct.

Multiple choice

Which one of the following is incorrectly matched?

  1. [Ag(NH3)2]+ and CO2 - Linear

  2. BF3 and CH3+ - Triangular planar

  3. NH3 and PCl3 - Pyramidal

  4. SF4 and CCl4 - Tetrahedral

  5. XeF4 and IF4 - Square planar
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This option is correct because the geometry of SF4 is see-saw due to the presence of 4 bond pairs and one lone pair of electrons (according to  VSEPR theory, its shape is seesaw), while the geometry of CCl4 is tetrahedral.

Multiple choice

Which of the following statements regarding the 1, 3-butadiene is/are false? A. The hybridisation of Carbon atom number 1 and 4 is sp2. B. The single bond between carbon atom number 2 and 3 is of the same length as the C-C bond length in ethane. C. 1, 3-butadiene is a conjugated diene.

  1. Only A

  2. Only B

  3. Only C

  4. Only B and C

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

Due to resonance C2-C3 bond has some double bond character, and hence its bond length (1.46 Ǻ) is shorter than the C-C bond length in ethane (1.54 Ǻ). Thus this option is correct.

Multiple choice

Which of the following compounds/molecules has dipole moment?

  1. HCl

  2. CO2 gas

  3. CH4

  4. N2
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

HCl molecules, have a dipole moment because the hydrogen atom has a slight positive charge and the chlorine atom has a slight negative charge. Because of the force of attraction between oppositely charged particles, there is a small dipole-dipole force of attraction between adjacent HCl molecules.

Multiple choice

Which halogen is a rare halogen?

  1. F

  2. Cl

  3. Br

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

The halogens are all chemically active. For that reason, none occur naturally in the form of elements. However—with the exception of astatine—they are very widespread and abundant in chemical compounds. Astatine is radioactive and is one of the rarest of the chemical elements. Astatine is generally regarded as one of the rarest naturally occurring elements. According to some estimates, no more than 44 milligrams of the element are to be found in Earth's crust.