In which of the following mixtures, the London dispersion force acts as major intermolecular force of attraction ?

Options

A. Sodium chloride and water
B. Cyclohexane and carbontetrachloride
C. Water and ethyl alcohol
D. Benzene and acetone.

Explanation

To determine in which of the following mixtures the London dispersion force acts as the major intermolecular force of attraction, we will analyze the given options step by step.

### Step 1: Understand London Dispersion Forces
London dispersion forces, also known as van der Waals forces, are weak intermolecular forces that arise from temporary dipoles formed when electron distributions in atoms or molecules fluctuate. These forces are significant in nonpolar molecules or noble gases.

### Step 2: Identify the Compounds
We need to identify the compounds in the given options. For this explanation, we will consider two compounds mentioned in the video: cyclohexane (C6H12) and carbon tetrachloride (CCl4).

### Step 3: Analyze the Nature of the Compounds
- **Cyclohexane (C6H12)**: This is a nonpolar hydrocarbon. It does not have a permanent dipole moment and primarily exhibits London dispersion forces.
- **Carbon Tetrachloride (CCl4)**: This is also a nonpolar molecule due to its symmetrical tetrahedral shape, despite having polar C-Cl bonds. The overall molecule does not have a permanent dipole moment, and thus, it also primarily exhibits London dispersion forces.

### Step 4: Determine the Major Intermolecular Force
Since both cyclohexane and carbon tetrachloride are nonpolar, the major intermolecular force acting between their molecules is the London dispersion force.

### Step 5: Conclusion
Based on the analysis, the mixture of cyclohexane and carbon tetrachloride is the one where London dispersion forces act as the major intermolecular force of attraction.

### Final Answer
The correct option is **B** (the mixture of cyclohexane and carbon tetrachloride).

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