Hydrogen bond is the given to the relatively weak secondry interaction between a hydrogen atom bound to an electronegative atom and another atom which is also generally electronegative and which has one or more lone pairs and can thus acts as a base. We can give the follwoing generalized representation of hydrogen bond.
`overset(delta-)(X)-overset(delta+)(H)...Y`
Bond dissociation energy of H-bond ranges from 8 and 42kJ/ol, and the most commonly encountred hydrogen bonds are `O-H...O, N-H...O and F-H..E`.
Q. Among molecules of HCl, which of the following forces are present.

Options

A. Interaction between two HCl molecules is found to be greater than 8kJ/mol
B. Weak dipole-dipole interaction
C. Weak ion-dipole interactions
D. All of above

Explanation

To determine the intermolecular forces present among molecules of HCl, we can follow these steps:

### Step 1: Identify the Nature of HCl
HCl is composed of hydrogen (H) and chlorine (Cl). The electronegativity difference between H and Cl is significant, making HCl a polar molecule.

**Hint:** Check the electronegativity values of the atoms involved to determine polarity.

### Step 2: Determine the Charge Distribution
In HCl, the hydrogen atom acquires a slight positive charge (δ+) due to its lower electronegativity, while the chlorine atom acquires a slight negative charge (δ-) because of its higher electronegativity.

**Hint:** Remember that in polar molecules, the more electronegative atom attracts the bonding electrons more strongly, creating partial charges.

### Step 3: Identify the Type of Intermolecular Forces
Since HCl is polar, the primary intermolecular force present is dipole-dipole interaction. This occurs because the positive end of one HCl molecule is attracted to the negative end of another HCl molecule.

**Hint:** Look for interactions between the positive and negative ends of polar molecules to identify dipole-dipole interactions.

### Step 4: Consider Hydrogen Bonding
Hydrogen bonding typically occurs when hydrogen is bonded to highly electronegative atoms such as fluorine, oxygen, or nitrogen. HCl does not contain these types of bonds, so it cannot form hydrogen bonds.

**Hint:** Recall the specific criteria for hydrogen bonding and check if HCl meets them.

### Step 5: Evaluate Other Interactions
While HCl does not exhibit hydrogen bonding, it may have weak ion-dipole interactions if HCl were to interact with ions in a solution. However, in the context of pure HCl molecules, the primary interaction remains dipole-dipole.

**Hint:** Consider the context of the question—whether it refers to pure HCl or a solution with ions.

### Conclusion
Among the molecules of HCl, the only significant intermolecular force present is weak dipole-dipole interaction.

**Final Answer:** The correct option is **2. Weak dipole-dipole interaction.**