Chemical Bonding And Molecular Structure

Step 1: Understanding the Concept:
A stable molecule is formed at the equilibrium separation , where the potential energy is at a minimum. This implies two conditions:
1. The net force is zero: at .
2. The potential energy at this point is equal to the negative of the binding energy (energy released): .
Step 2: Key Formula or Approach:
Given .
First, find the derivative and set it to zero:

At , :

Second, use the binding energy information:

Step 3: Detailed Explanation:
We have the following given values:
eV = J J
Å = m
Substitute the expression for A into the energy equation:



Now, calculate B:



This matches J m .
Next, find A using the relation derived from the energy at equilibrium:
Calculate A:



Step 4: Final Answer:
The calculated values are A J m and B J m . These values are in excellent agreement with option (A).

Step 1: Understanding the Concept:
This question requires matching different types of chemical bonds with their correct descriptions.
Step 2: Detailed Explanation:
A. Ionic Bonds: These are formed by the electrostatic attraction between oppositely charged ions. This happens through the complete transfer of one or more electrons from one atom to another. This matches description II.
B. Metallic Bonds: This type of bonding involves a 'sea' of delocalized electrons that are shared among a lattice of positive metal ions. Description I, "Partial sharing of valence electrons by the neighboring atoms," is the closest available description, though it more accurately describes covalent bonding. In the context of the given options, metallic bonding is a form of electron sharing.
C. Van der Waals Bonds: These are weak, secondary bonds that arise from temporary or permanent dipoles in atoms or molecules. They are a general category of dipolar interactions. Description IV, "This type of bonding arises from dipolar interaction of crystals/molecules of the crystal," is a suitable general description for these forces.
D. Hydrogen Bonds: This is a special, strong type of dipole-dipole interaction. It occurs when a hydrogen atom is bonded to a highly electronegative atom (like N, O, or F) and is attracted to another electronegative atom nearby. This corresponds to an interaction between permanently polarized molecules. This perfectly matches description III.
Step 3: Final Answer:
The correct matching is:

A II
B I
C IV
D III
This corresponds to option (B).