5.3 Study Guide

Question 1

Describe London Dispersion and how it creates temporary bonds between particles.

Answer 1

London Dispersion is an event that occurs occasionally in a neutral atom or molecule in which its electrons, in their elliptical orbits, randomly group together near the farthest orbital point from the particle and cause the particle to become temporarily polar (partially charged at each end). This allows it to easily form polar bonds with other particles until its electrons return to standard, balanced orbits and make the particle neutral once again,

Question 2

Describe Dipole-Dipole bonding. Explain why most Hydrogen Dipole-Dipole bonds are so strong.

Answer 2

Dipole-Dipole bonding is a form of molecular bonding in which polar molecules are attracted to each other and stick together due to their oppositely charged ends. Most Hydrogen Dipole-Dipole bonds are so strong because they take place between a Hydrogen atom and an atom of an element with a large difference in electronegativity compared to Hydrogen.

Question 3

Write the 3 intermolecular bonds focused on in this unit in order from lowest force to highest force.

Answer 3

London Dispersion Forces (lowest)
Dipole-Dipole Bonding (middle)
Hydrogen Bonding (highest)

Question 4

(5 different molecules are shown; they are Water, Methyl Alcohol, Methane, Acetic Acid, and Hexane) Of these 5 molecules, state which are polar and which are non-polar.

Answer 4

Polar Molecules: Water, Methyl Alcohol, and Acetic Acid (include polar covalent bonds and are electronegatively imbalanced).
Non-Polar Molecules: Methane and Hexane (both electronegatively balanced).

Question 5

(3 different molecules are shown; they are Water, Fluoromethane, and Carbon Dioxide) Explain which forms of intermolecular interaction each molecule will be able to perform based on its structure.

Answer 5

Water will be able to perform London Dispersion Bonding, Dipole-Dipole Bonding, and Hydrogen Bonding due to its electrons, its polarity, and its polar covalent bonds between hydrogen and oxygen.
Fluoromethane will be able to perform London Dispersion Bonding and Dipole-Dipole Bonding due to its electrons and polarity, but it will not be able to perform Hydrogen Bonding due to it having no polar covalent bonds between Hydrogen and an atom with significantly different electronegativity.
Carbon Dioxide will be able to perform London Dispersion Bonding due to its electrons, but it will not be able to perform Dipole-Dipole Bonding or Hydrogen Bonding due to its neutrality and lack of hydrogen atoms.

Question 6

(4 molecules are shown; they are Methyl Alcohol, Hexane, Acetic Acid, and Oil) State which molecules will be water-soluble or not based on their structure and explain why.

Answer 6

Methyl Alcohol and Acetic Acid will be water-soluble because of their polarity, which gives them a high tendency to bond with other polar atoms like water. Hexane and Oil will not be water-soluble because of their neutrality or insignificant polarity, which gives them a low tendency to bond with polar atoms like water.