Final answer:
The bond order of a covalent bond determines its strength. Using MO diagrams, we can calculate the bond order for different pairs of molecules. The molecule with a higher bond order will have a stronger bond. For example, B₂⁺ has a stronger bond than B₂.
Step-by-step explanation:
The bond order is a measure of the strength of a covalent bond. It is calculated by subtracting the number of antibonding electrons from the number of bonding electrons and dividing by two. The higher the bond order, the stronger the bond.
(a) B₂: In B₂, there are 4 bonding electrons and 2 antibonding electrons. Therefore, the bond order is (4-2)/2 = 1. B₂⁺: In B₂⁺, there are 4 bonding electrons and 1 antibonding electron. Therefore, the bond order is (4-1)/2 = 1.5. Based on the bond order, B₂⁺ has a stronger bond.
(b) F₂: In F₂, there are 8 bonding electrons and 6 antibonding electrons. Therefore, the bond order is (8-6)/2 = 1. F₂⁺: In F₂⁺, there are 8 bonding electrons and 5 antibonding electrons. Therefore, the bond order is (8-5)/2 = 1.5. Based on the bond order, F₂⁺ has a stronger bond.
(c) O₂: In O₂, there are 12 bonding electrons and 4 antibonding electrons. Therefore, the bond order is (12-4)/2 = 4. O₂²⁺: In O₂²⁺, there are 12 bonding electrons and 5 antibonding electrons. Therefore, the bond order is (12-5)/2 = 3.5. Based on the bond order, O₂ has a stronger bond.
(d) C₂⁺: In C₂⁺, there are 4 bonding electrons and 1 antibonding electron. Therefore, the bond order is (4-1)/2 = 1.5. C₂⁻: In C₂⁻, there are 4 bonding electrons and 3 antibonding electrons. Therefore, the bond order is (4-3)/2 = 0.5. Based on the bond order, C₂⁺ has a stronger bond.