NEET2016ChemistryChemical Bonding and Molecular StructureActual
Four diatomic species are listed below in different sequences. Which of these represents the correct order of their increasing bond order?
Options
- AC ₂²⁻ < He ₂⁺ < NO < O ₂⁻
- BHe ₂⁺ < O ₂⁻ < NO < C ₂²⁻
- CO ₂⁻ < NO < C ₂²⁻ < He ₂⁺
- DNO < C ₂²⁻ < O ₂⁻ < He ₂⁺
Correct answer
B. He ₂⁺ < O ₂⁻ < NO < C ₂²⁻
Step-by-step solution
According to molecular orbital theory, the energy level of the given molecules are aligned & C ₂²⁻ 1 s^2 ^ 1 s^2 2 s^2 ^ 2 s^2 2 p_x^2 2 p_y^2 2 p_z^2 & B.O. =1 / 2[10-4]=3 & He ₂⁺ 1 s^2 ^ 1 s^1 & B.O. =1 / 2[2-1]=1 / 2=0.5 & NO 1 s^2 ^ 1 s^2 2 s^2 ^ 2 s^2 2 p_z^2 2 p_x^2 2 p_y^2 & ^ 2 p_x^1 aligned aligned & B.O. =1 / 2[10-5]=2.5 & O ₂⁻ 1 s^2 ^ 1 s^2 2 s^2 ^ 2 s^2 2 p_z^2 2 p_x^2 2 p_y^2 ^ 2 p_x^2 & B.O. =1 / 2[10-7]=1.5 & ^ 2 p_y^1 & aligned So, the correct order of their increasing bond order is He ₂⁺ < O ₂⁻ < N