Consider the following pure liquid compounds resting at standard room temperature: 1. 1-chlorobutane — Haloalkanes and Haloarenes Chemistry Question
Question
Consider the following pure liquid compounds resting at standard room temperature: 1. 1-chlorobutane 2. Dichloromethane 3. Chloroform 4. Carbon tetrachloride 5. Methyl iodide 6. Bromobenzene If equal volumes of each pure liquid are individually mixed with an equal volume of pure water in completely separate test tubes, how many of these specific mixtures will result in the organic layer cleanly sinking to the bottom (i.e., organic density > water density)?
💡 Solution & Explanation
Whether an insoluble organic layer floats or sinks depends entirely on its density relative to water ($1.0$ g/mL). 1) Monochloroalkanes (like 1-chlorobutane) are exclusively lighter than water and will float. 2, 3, 4) Polyhalogenated aliphatic compounds (like $CH_2Cl_2, CHCl_3, CCl_4$) are distinctly heavier than water and will sink. 5) All alkyl bromides and alkyl iodides (like $CH_3I$) are heavier than water due to the massive atomic weight of the halogens and will sink. 6) Aryl bromides (like bromobenzene) and aryl iodides are also heavier than water and will sink. Therefore, exactly 5 of these compounds ($CH_2Cl_2, CHCl_3, CCl_4, CH_3I,$ and bromobenzene) will sink.