arrange the followin in the increasing b. p. . penatne, hexane and 2,3-dimethylbutane.

To arrange the compounds penane, hexane, and 2,3-dimethylbutane in order of increasing boiling points, we need to consider their molecular structures and the factors that influence boiling points, such as molecular weight and branching.

Understanding Boiling Points

The boiling point of a substance is influenced by several factors, including:

• Molecular Weight: Generally, as molecular weight increases, boiling points tend to increase due to stronger van der Waals forces.
• Branching: More branched molecules typically have lower boiling points than their straight-chain isomers because branching reduces surface area, leading to weaker intermolecular forces.

Analyzing Each Compound

Let’s take a closer look at each of the compounds:

• Penane (C5H12): This is a straight-chain alkane with five carbon atoms. Its boiling point is relatively high due to its linear structure, which allows for more effective packing and stronger van der Waals forces.
• Hexane (C6H14): Hexane is another straight-chain alkane, but with six carbon atoms. It has a higher molecular weight than penane, which typically results in a higher boiling point.
• 2,3-Dimethylbutane (C7H16): This compound is a branched alkane. Although it has a higher molecular weight than both penane and hexane, its branching reduces the effective surface area for intermolecular interactions, which can lower its boiling point compared to straight-chain alkanes.

Arranging the Compounds

Now, let’s summarize the boiling points based on the analysis:

• Penane has the lowest boiling point due to its lower molecular weight and linear structure.
• 2,3-Dimethylbutane, despite having a higher molecular weight, has a lower boiling point than hexane due to its branched structure.
• Hexane has the highest boiling point because it is a straight-chain alkane with a higher molecular weight than penane and less branching than 2,3-dimethylbutane.

Final Order

Therefore, the order of increasing boiling points is:

1. Penane
2. 2,3-Dimethylbutane
3. Hexane

This arrangement reflects the interplay between molecular weight and structural branching, which are key factors in determining boiling points in organic compounds.