Ionic
Ionic bonding is between a(n) ___ and a(n) ____.
Ion, ion
Dipole-dipole interactions have to occur between two _____ molecules.
Polar
True or false: hydrogen bonding is the strongest IMF
It's stronger than dipole-dipole and London Dispersion, but not ionic or ion-dipole
True or false: London dispersion is present in all molecules
True
London dispersion comes from a temporary dipole moment due to the movement of elements within the molecule
True or false: intermolecular forces determine different physical properties such as boiling point, vapor pressure, viscosity, and surface tension
True
When you dissolve something in water, what type of IMF is strongest?
Ion-dipole
Explain why a dipole-dipole interaction occurs (specifically explain dipole moment or why the two ends of the molecules interact)
The partial positive (δ⁺) charge of one end of a polar molecule interacts with the partial negative charge (δ⁻) of the end of another polar molecule, allowing the two dipole moments to interact and create a dipole-dipole interaction.
Hydrogen bonding is between hydrogen and what other element(s)? (Hint: there are three possible elements)
Fluorine, oxygen, nitrogen
Will a London dispersion force be stronger in a larger or smaller molecule?
A larger molecule
Larger molecules have more electrons and have a higher chance of creating temporary dipole moments
Rank the following IMFs in order of strongest to weakest (in general!).
Ionic, dipole-dipole, hydrogen bonding, London dispersion, ion-dipole
Ionic > ion-dipole > hydrogen bonding > dipole-dipole > London dispersion
When you put a typically insoluble compound in water, why does it not dissolve? (Hint: it has to do with IMFs!)
The ionic bond is stronger than the possible ion-dipole interaction with water. The ionic bond is too strong to break.
Which of these molecules can exhibit dipole–dipole interactions: CO₂, H₂O, CH₄, NH₃?
H2O and NH3
They are both polar (a dipole moment is present). CO2 and CH4 are nonpolar, so they are unable to form dipole-dipole interactions.
What are the exact requirements for hydrogen bonding to occur? Think of examples of when it DOESNT occur to help.
1. Must be a dipole moment between hydrogen and O, F, or N.
2. O, F, or N must have a lone pair for the hydrogen to interact with
3. The H must already be covalently bonded to O, F, or N (ex: NH3 is bonded to N, can form a hydrogen bond, but CH3 won't because no hydrogens are already bonded to O, F, or N)
Which of these two molecules will have a higher IMF.
CH4, C6H12
C6H12
Both have only London dispersion; C6H12 has a larger molecular weight
Determine the intermolecular forces present in the following compound: CH₃Br
London-dispersion, dipole-dipole
Determine which of the following is an ionic bond: NH3, CaO, H2, CO2, PCl3
CaO
Ca2+ and O2-
Will a dipole-dipole interaction occur between the following molecules: CH4 and CH4? Why or why not?
No, CH4 is nonpolar
Which can form hydrogen bonds: HF, CH₃OH, CH₄, or H₂S?
HF and CH3OH
True or false: London dispersion is the only IMF in nonpolar molecules
True
Determine the intermolecular forces in the following compound: CH₃CH₂CH₂OH
London dispersion, hydrogen bonding, dipole-dipole
Which of the following would result in an ion-dipole interaction: CO2 and C6H6, CH3OH and HCl, HCl and CH4?
CH3OH and HCl
Which pair of molecules exhibits dipole–dipole interactions? Explain why.
CO2 and CH3
N2 and O2
SO2 and SO2
SO2 and SO2, both are polar molecules
Predict which compound has the strongest : C7H8O, C6H4(OH)2, C6H5OH
C6H4(OH)2
It has two hydrogen bonds vs C6H5OH which only has one and C7H8O which has none. Higher IMF = higher boiling point.
Rank these molecules from highest to lowest vapor pressure: CH₄, C₃H₈, and C₈H₁₈
CH4 > C3H8 > C8H18
Weaker IMFs = higher vapor pressure, only London dispersion is present, so higher MW = stronger IMFs