Molecular orbital theory, bond order and magnetic properties — practice questions

Question 1 · difficulty L2 · understanding

The total number of molecular orbitals formed from $$2 \mathrm{s}$$ and $$2 \mathrm{p}$$ atomic orbitals of a diatomic molecule is __________.

Question 2 · difficulty L2 · understanding

The total number of anti bonding molecular orbitals, formed from $$2 s$$ and $$2 p$$ atomic orbitals in a diatomic molecule is _______.

Question 3 · difficulty L2 · understanding

Sum of bond order of CO and NO$$^+$$ is ________.

Question 4 · difficulty L2 · understanding

The spin-only magnetic moment value of $$B_2^ +$$ species is _____________ $$\times$$ 10 $$-$$2 BM. (Nearest integer) [Given : $$\sqrt 3$$ = 1.73]

Question 5 · difficulty L2 · understanding

According to molecular orbital theory, the number of unpaired electron(s) in $$O_2^{2 - }$$ is :

Question 6 · difficulty L2 · understanding

The difference between bond orders of CO and NO$$^ \oplus$$ is $${x \over 2}$$ where x = _____________. (Round off to the Nearest Integer)

Question 7 · difficulty L2 · understanding

Which of the following molecule(s) show/s paramagnetic behavior? A. $\mathrm{O}_2$ B. $\mathrm{N}_2$ C. $\mathrm{F}_2$ D. $\mathrm{S}_2$ E. $\mathrm{Cl}_2$ Choose the correct answer from the options given below:

• A. A & C only
• B. A & E Only
• C. A & D Only
• D. B Only

Question 8 · difficulty L2 · understanding

When $$\psi_{\mathrm{A}}$$ and $$\psi_{\mathrm{B}}$$ are the wave functions of atomic orbitals, then $$\sigma^*$$ is represented by :

• A. $$\psi_A+2 \psi_B$$
• B. $$\psi_{\mathrm{A}}-\psi_{\mathrm{B}}$$
• C. $$\psi_A-2 \psi_B$$
• D. $$\psi_{\mathrm{A}}+\psi_{\mathrm{B}}$$

Question 9 · difficulty L2 · understanding

The linear combination of atomic orbitals to form molecular orbitals takes place only when the combining atomic orbitals A. have the same energy B. have the minimum overlap C. have same symmetry about the molecular axis D. have different symmetry about the molecular axis Choose the most appropriate from the options given below:

• A. B, C, D only
• B. A, B, C only
• C. B and D only
• D. A and C only

Question 10 · difficulty L2 · understanding

Consider the ions/molecule O$$_2^ +$$, O 2 , O$$_2^ -$$, O$$_2^ {2-}$$ For increasing bond order the correct option is :

• A. O$$_2^ {2-}$$ < O$$_2^ -$$ < O 2 < O$$_2^ +$$
• B. O$$_2^ -$$ < O$$_2^ {2-}$$ < O 2 < O$$_2^ +$$
• C. O$$_2^ -$$ < O$$_2^ {2-}$$ < O$$_2^ +$$ < O 2
• D. O$$_2^ -$$ < O$$_2^ +$$ < O$$_2^ {2-}$$ < O 2