Consider the following equimolar pure liquid samples: 1. n-propyl chloride 2. isopropyl chloride 3. — Haloalkanes and Haloarenes Chemistry Question
Question
Consider the following equimolar pure liquid samples: 1. n-propyl chloride 2. isopropyl chloride 3. 1-chlorobutane 4. 2-chloro-2-methylpropane 5. 1-chloropentane If they are arranged in strictly increasing order of their normal boiling points, what is the assigned index number of the specific compound that sits exactly in the middle (the median) of the resulting series?
💡 Solution & Explanation
First, group by molecular mass. Boiling point increases with mass: $C_3 < C_4 < C_5$. $C_3$ compounds: Isopropyl chloride (branched) < n-propyl chloride (straight). $C_4$ compounds: 2-chloro-2-methylpropane (highly branched) < 1-chlorobutane (straight). $C_5$ compound: 1-chloropentane (highest mass). The strictly increasing overall sequence is: isopropyl chloride < n-propyl chloride < 2-chloro-2-methylpropane < 1-chlorobutane < 1-chloropentane. The median (3rd out of 5) is 2-chloro-2-methylpropane, which corresponds to index number 4.