which of the molecules listed below can form hydrogen bonds? for which of the molecules would dispersion forces be the only intermolecular force? give reasons for you answers.
no list
To determine which molecules can form hydrogen bonds and for which molecules dispersion forces would be the only intermolecular force, we need to understand the characteristics of each molecule and the type of intermolecular forces they exhibit.
Hydrogen bonding occurs when a hydrogen atom is bonded to an electronegative atom (such as oxygen, nitrogen, or fluorine) and is attracted to another electronegative atom in another molecule. This creates a strong dipole-dipole interaction and results in the formation of hydrogen bonds.
On the other hand, dispersion forces (also known as London dispersion forces) are the intermolecular forces that occur between all molecules, regardless of their polarity. These forces are caused by temporary fluctuations in the electron distribution, creating temporary dipoles.
To determine which molecules can form hydrogen bonds, we need to consider whether the molecules have a hydrogen atom bonded to a highly electronegative atom (O, N, or F), and whether they are attracted to another electronegative atom.
For molecules with hydrogen bonding:
1. Water (H₂O): It has hydrogen atoms bonded to an oxygen atom, allowing it to form hydrogen bonds with other water molecules.
2. Ethanol (CH₃CH₂OH): It has a hydrogen atom bonded to an oxygen atom, allowing it to form hydrogen bonds with other ethanol molecules.
3. Ammonia (NH₃): It has a hydrogen atom bonded to a nitrogen atom, allowing it to form hydrogen bonds with other ammonia molecules.
For molecules where dispersion forces are the only intermolecular force:
1. Methane (CH₄): It does not have hydrogen bonding potential since it lacks an electronegative atom directly bonded to hydrogen. However, it can still have dispersion forces due to temporary fluctuations in electron distribution.
2. Carbon tetrachloride (CCl₄): It does not have hydrogen bonding potential since it lacks an electronegative atom directly bonded to hydrogen. It can only exhibit dispersion forces.
In summary, molecules that can form hydrogen bonds have a hydrogen atom bonded to an electronegative atom (oxygen, nitrogen, or fluorine) and are attracted to another electronegative atom in another molecule. Molecules where dispersion forces are the only intermolecular force lack hydrogen atoms bonded to highly electronegative atoms.