Functional Groups and Polarity

Question 1

List the common function groups in order of least polar to greatest

Answer 1

Least = hydrocarbons, aldehydes &ketones, amines, alcohols, carboxylic acids, charged molecules = most

Question 2

What are amphipathic molecules?

Answer 2

Molecules that have polar and non-polar portions

Example: Fatty acid chain

Question 3

How are polarity and solubility related?

Answer 3

Like goes with like, so polar molecules soluble in polar solvents
Typically polar solvents are aqueous solutions
non-polar are lipid rich

Question 4

Polar

Answer 4

aka: water-soluble, hydrophilic, lipophobic
molecule with 1 or more electronegative atoms
dipole > 0.5 typically means molecule is polar, as long as the dipoles of other bonds don’t cancel it out
Could have a dipole - so an atom could be polar because it has tendency to pull electrons towards it
Or you could have a full positive or negative charge in the case where it’s an ion, or the atom steels electrons
Example; H2O (oxygen hogs the electrons from)
Phosphate PO3-
Na+

Question 5

Non-polar

Answer 5

aka: non water-soluble, hydrophobic, lipophilic
weak dipole (less than 0.5), or when there is a bulky arrangement that overcome the dipole of other molecules, or where there is