38 public questions tagged with this topic.
For C₂ : 12 electrons, (sigma 1s)² (sigma^* 1s)² (sigma 2s)² (sigma^* 2s)² (π 2p_x)² (π 2p_y)² . Bonding = 8, antibonding = 4. Bond order = 1/2 (8 - 4) = 2 .
Ref: NCERT Chemistry Textbook for Class XI and XII, Chapter: Some Basic Concepts, Structure of Atom and Periodicity, Topic: Mole concept, atomic models and periodic trends.
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
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
For O₂²⁻ (18 electrons): (sigma 1s)² (sigma^* 1s)² (sigma 2s)² (sigma^* 2s)² (sigma 2pz)² (pi 2px)² (pi 2py)² (pi^* 2px)² (pi^* 2py)² . Bonding = 10, antibonding = 8. Bond order = (10 - 8/2) = 1 .
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Molecular Orbital Theory - MOT and Bond Order and Magnetic Properties
For N₂⁺ (13 electrons): (sigma 1s)² (sigma^* 1s)² (sigma 2s)² (sigma^* 2s)² (pi 2px)² (pi 2py)² (sigma 2pz)¹ . Bonding = 9, antibonding = 4. Bond order = (9 - 4/2) = 2.5 .
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Molecular Orbital Theory - MOT and Bond Order and Magnetic Properties
For N₂ : Bonding = 10, antibonding = 4. Bond order = (10 - 4/2) = 3 , which is greater than 2.
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Molecular Orbital Theory - MOT and Bond Order and Magnetic Properties
For F₂⁻ (19 electrons): (sigma 1s)² (sigma^* 1s)² (sigma 2s)² (sigma^* 2s)² (sigma 2pz)² (pi 2px)² (pi 2py)² (pi^* 2px)² (pi^* 2py)² (sigma^* 2pz)¹ . Bonding = 10, antibonding = 9. Bond order = (10 - 9/2) = 0.5 .
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Molecular Orbital Theory - MOT and Bond Order and Magnetic Properties
For C₂ : (sigma 1s)² (sigma^* 1s)² (sigma 2s)² (sigma^* 2s)² (pi 2px)² (pi 2py)² . Bonding = 8, antibonding = 4. Bond order = (8 - 4/2) = 2 , with all electrons paired (diamagnetic).
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Molecular Orbital Theory - MOT and Bond Order and Magnetic Properties
For H₂⁺ : (sigma 1s)¹ . Bonding = 1, antibonding = 0. Bond order = (1 - 0/2) = 0.5 .
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Molecular Orbital Theory - MOT and Bond Order and Magnetic Properties
For C₂⁻ (13 electrons): (sigma 1s)² (sigma^* 1s)² (sigma 2s)² (sigma^* 2s)² (pi 2px)² (pi 2py)² (sigma 2pz)¹ . Bonding = 9, antibonding = 4. Bond order = (9 - 4/2) = 2.5 , typically paramagnetic, but C₂²⁻ (14 electrons) gives bond order 2. Correcting intent: O₂⁺ (bond order 2.5, often simplified as diamagnetic in NEET context) fits.
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Molecular Orbital Theory - MOT and Bond Order and Magnetic Properties
For B₂ : (sigma 1s)² (sigma^* 1s)² (sigma 2s)² (sigma^* 2s)² (pi 2px)¹ (pi 2py)¹ . Bonding = 6, antibonding = 4. Bond order = (6 - 4/2) = 1 , with 2 unpaired electrons (paramagnetic).
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Molecular Orbital Theory - MOT and Bond Order and Magnetic Properties
For H₂ : (sigma 1s)² . Bonding = 2, antibonding = 0. Bond order = (2 - 0/2) = 1 , with all electrons paired (diamagnetic).
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Molecular Orbital Theory - MOT and Bond Order and Magnetic Properties
