Final answer:
CH3NH2 (methylamine) is the substance that has hydrogen bonding in the pure liquid phase because it has hydrogen atoms bonded to a highly electronegative atom, nitrogen, which allows for hydrogen bonding.
Step-by-step explanation:
The question asks about which substance has hydrogen bonding in the pure liquid phase. Hydrogen bonds are a type of strong dipole-dipole attraction that occurs when a hydrogen atom bonded to a highly electronegative atom, such as nitrogen, oxygen, or fluorine, is attracted to another electronegative atom in a different molecule. Among the options provided, CH3NH2 (methylamine) has hydrogen atoms bonded to nitrogen, which is a highly electronegative atom, making it capable of forming hydrogen bonds. Therefore, in the pure liquid phase, CH3NH2 would exhibit hydrogen bonding. The other compounds listed, such as H2S, CCl4, NaCl, and CH3Br, do not meet the criteria for forming hydrogen bonds in their pure states.