Reasons why Propan-1-ol boils at a higher temperature than Propan-2-ol:
Propan-1-ol, also known as 1-propanol, has a higher boiling point compared to propan-2-ol, also known as 2-propanol. This difference in boiling points can be attributed to the structural differences between the two isomers.

Hydrogen Bonding:
- Propan-1-ol can engage in intermolecular hydrogen bonding due to the presence of a hydroxyl group (OH) at the end of the carbon chain.
- This hydrogen bonding results in stronger intermolecular forces between propan-1-ol molecules, requiring more energy to break these bonds and boil the liquid.

Branching Effect:
- Propan-2-ol has a branched structure with the hydroxyl group attached to a secondary carbon atom, leading to less efficient hydrogen bonding compared to propan-1-ol.
- The branching in propan-2-ol disrupts the alignment of molecules, weakening the intermolecular forces and lowering the boiling point.

Van der Waals Forces:
- Both propan-1-ol and propan-2-ol exhibit Van der Waals forces, but the presence of hydrogen bonding in propan-1-ol enhances these forces, contributing to a higher boiling point.

Conclusion:
In summary, the higher boiling point of propan-1-ol compared to propan-2-ol can be attributed to the presence of hydrogen bonding due to the hydroxyl group at the end of the carbon chain. This stronger intermolecular force in propan-1-ol requires more energy input to overcome, resulting in a higher boiling point.