Final answer:
Methylene chloride (CH2Cl2) has a density of 1.327 g/mL, which is greater than that of water, so it would sink in water.
Step-by-step explanation:
Methylene chloride, also known as dichloromethane (CH2Cl2), is more dense than water. In general, haloalkanes, which include chloroalkanes, are denser than alkanes. While mono-chloroalkanes are usually less dense than water, molecules with multiple chlorine atoms, such as di-, tri- and tetra-chloroalkanes, have densities higher than water. Methylene chloride, being a dichloroalkane, has a density of 1.327 g/mL at 25 °C, which is significantly higher than the density of water at the same temperature (approximately 1.0 g/mL). This means methylene chloride would sink in water.