Chemical Bonding And Molecular Structure

All the given statements are correct.

Step 1: Understanding the Concept:
The number of unpaired electrons can be determined from the molecular orbital (MO) electronic configuration.
Step 2: Detailed Explanation:
\begin{itemize} \item (A) NO: 15 electrons. MO configuration: . One unpaired electron. \item (B) CO: 14 electrons. MO configuration: . No unpaired electrons. \item (C) CN : 14 electrons (C has 6, N has 7, plus 1 extra = 14). Same as CO, no unpaired electrons. \item (D) O : 16 electrons. MO configuration: . Two unpaired electrons. \end{itemize}
Step 3: Final Answer:
NO has one unpaired electron, option (A).

Step 1: Understanding the Concept:
Paramagnetic substances have unpaired electrons.
Step 2: Detailed Explanation:
has two unpaired electrons in orbitals, hence paramagnetic.
Step 3: Final Answer:
is paramagnetic.

Step 1: Understanding the Concept:
Bond order determines bond strength.
Step 2: Detailed Explanation:
Bond order: (2), (1.5), (1). Bond strength decreases with bond order.
Step 3: Final Answer:
.

Step 1: Understanding the Concept:
Bond order = .
Step 2: Detailed Explanation:
has electronic configuration , bond order = .
Step 3: Final Answer:
has zero bond order.

Step 1: Understanding the Concept:
More electronegative atom should have negative charge.
Step 2: Detailed Explanation:
A more electronegative, so A B (III) contributes most.
A B (II) has positive charge on A, least contribution.
Step 3: Final Answer:
Structure II contributes least.

Step 1: Understanding the Concept:
Ionic bonds are non-directional electrostatic forces.
Step 2: Detailed Explanation:
Ionic bonds are non-directional due to spherical symmetry of ions.
Step 3: Final Answer:
Ionic crystals do not have directional bonds.

Step 1: Understanding the Concept:
Both have same geometry (linear).
Step 2: Detailed Explanation:
XeF : sp d hybridization, linear geometry.
ICl also has linear geometry.
Step 3: Final Answer:
XeF is isostructural with ICl .

Step 1: Understanding the Concept:
Molecular orbital configuration of O .
Step 2: Detailed Explanation:
O has configuration: ... ( 2p ) ( 2p ) ( 2p )
Removing electron from bonding -orbital.
Step 3: Final Answer:
Electron lost from bonding -orbital.

Step 1: Understanding the Concept:
Both are oxides of group 14 elements.
Step 2: Detailed Explanation:
CO + NaOH NaHCO , SiO + 2NaOH Na SiO + H O
Both react with bases to form salts.
Step 3: Final Answer:
Both are acidic oxides.

Step 1: Understanding the Concept:
Hückel's rule: aromatic if (4n+2) -electrons.
Step 2: Detailed Explanation:
Benzene: 6 -electrons (n=1)
Naphthalene: 10 -electrons (n=2)
Step 3: Final Answer:
6 and 10 -electrons.

Step 1: Understanding the Concept:
Bond order = .
Step 2: Detailed Explanation:
O : BO = 1, O : BO = 1.5, O : BO = 2, O : BO = 2.5
Increasing order: 1, 1.5, 2, 2.5
Step 3: Final Answer:
O , O , O , O .