Understanding Miscibility

Miscibility refers to the ability of two liquids to mix and form a homogeneous solution. This is largely determined by the polarity of the molecules involved:

* Polar Molecules: Have uneven distribution of electrons, leading to partial positive and negative charges. They tend to dissolve in other polar solvents.

* Nonpolar Molecules: Have even distribution of electrons and no significant partial charges. They tend to dissolve in other nonpolar solvents.

Analyzing the Substances

1. CH3CH2CH2CH2CH3 (Pentane) and CH3CH2CH2CH2CH2CH3 (Hexane): Both are alkanes, which are hydrocarbons with only single bonds. This makes them nonpolar. Since they are both nonpolar, they are miscible.

2. CBr4 (Carbon Tetrabromide): While carbon has a slightly higher electronegativity than bromine, the tetrahedral shape of CBr4 cancels out the dipole moments. This makes it nonpolar.

3. H2O (Water): Due to the difference in electronegativity between hydrogen and oxygen, water molecules are highly polar.

4. Cl2 (Chlorine): Chlorine is a diatomic molecule with a nonpolar covalent bond. It is nonpolar.

Determining Miscibility

* Pentane/Hexane and CBr4: All three are nonpolar, so they will be miscible.

* Pentane/Hexane and H2O: These are nonpolar and polar, respectively. "Like dissolves like", meaning they will be immiscible (won't mix).

* CBr4 and H2O: Again, nonpolar and polar, making them immiscible.

* Cl2 and H2O: Nonpolar and polar, leading to immiscibility.

Summary:

* CH3CH2CH2CH2CH3 and CH3CH2CH2CH2CH2CH3 are miscible with CBr4.

* All other combinations are immiscible.