Propanol, CH\(_3\)CH\(_2\)CH\(_2\)OH has the highest boiling point among ethanol,(CH\(_3\)CH\(_2\)OH) propanol,(CH\(_3\)CH\(_2\)CH\(_2\)OH) hexane,(CH\(_3\)CH\(_2\)CH\(_2\)CH\(_2\)CH\(_2\)CH\(_3\) )and chloropropane, (CH\(_3\)CH\(_2\)CH\(_2\)Cl ) because its longer carbon chain and ability to hydrogen bond (like ethanol) create stronger intermolecular forces, requiring more energy to vaporize, with propanol (around 97°C) significantly beating ethanol (~78°C), hexane (~69°C), and chloropropane (similar to hexane/slightly higher due to polarity but less H-bonding than alcohols).