Practice questions and explanations covering chemical bonding and molecular structure, including covalent, ionic, and intermolecular forces, to help students prepare for chemistry exams.
In C₂H₄ (ethene), the C=C double bond has a bond length of ~134 pm, typical for carbon-carbon double bonds.
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Valence Bond Theory and Hybridisation - sp sp2 sp3 dsp2
In H₃NBF₃ , nitrogen in NH₃ donates a lone pair to boron in BF₃ , forming a coordinate bond.
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Valence Bond Theory and Hybridisation - sp sp2 sp3 dsp2
For He₂ : (sigma 1s)² (sigma^* 1s)² . Bonding = 2, antibonding = 2. Bond order = (2 - 2/2) = 0 , so it does not exist.
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Valence Bond Theory and Hybridisation - sp sp2 sp3 dsp2
N₂ has a triple bond with a bond enthalpy of ~946 kJ/mol, higher than O₂ (498 kJ/mol), F₂ (159 kJ/mol), or Cl₂ (243 kJ/mol).
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Valence Bond Theory and Hybridisation - sp sp2 sp3 dsp2
In cyclopentadiene ( CH=CH-CH=CH-CH₂ in a ring), there are 2 double bonds, each with 1 pi bond, totaling 2 pi bonds, plus 13 sigma bonds.
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Valence Bond Theory and Hybridisation - sp sp2 sp3 dsp2
In BH₃ , boron is sp² hybridized with 3 bonding pairs and no lone pairs, forming a trigonal planar shape with 120° bond angles.
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Valence Bond Theory and Hybridisation - sp sp2 sp3 dsp2
In CO₂ , each C=O double bond has a bond length of ~123 pm, shorter than C=C in ethene (134 pm) due to higher bond strength.
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Valence Bond Theory and Hybridisation - sp sp2 sp3 dsp2
In SO₂ , sulfur has three electron domains (two bonds, one lone pair), requiring sp² hybridization, leading to a bent shape.
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Valence Bond Theory and Hybridisation - sp sp2 sp3 dsp2
For O₂⁺ : (sigma 1s)² (sigma^* 1s)² (sigma 2s)² (sigma^* 2s)² (sigma 2pz)² (pi 2px)² (pi 2py)² (pi^* 2px)¹ . Bonding = 10, antibonding = 5. Bond order = (10 - 5/2) = 2.5 .
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Valence Bond Theory and Hybridisation - sp sp2 sp3 dsp2
In XeF₄ , xenon has 6 electron pairs (4 bonding, 2 lone) with sp³d² hybridization, giving an octahedral electron geometry and a square planar shape.
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Valence Bond Theory and Hybridisation - sp sp2 sp3 dsp2
In AsF₅ , arsenic uses one s, three p, and one d orbital to form five sp³d hybrid orbitals, giving a trigonal bipyramidal shape.
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Valence Bond Theory and Hybridisation - sp sp2 sp3 dsp2
In XeF₆ , xenon has 8 valence electrons, forms 6 bonds (12 electrons used), leaving 2 electrons as 1 lone pair. With 7 electron pairs (6 bonding, 1 lone), it adopts sp³d² hybridization, forming an octahedral electron geometry with a distorted octahedral molecular shape due to lone pair repulsion.
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Valence Bond Theory and Hybridisation - sp sp2 sp3 dsp2
