Exp 1: Physical Properties of Organic Solvents Flashcards
Describe some properties of a solvent.
- how miscible it is with water
- what the density is
- what the boiling point is
- what other kinds of molecule it will dissolve
What properties of a liquid determine whether it is water-miscible?
- whether or not the molecular forces in the solvent are similar to the molecular forces in water
- the more similar IMFs are to those between water molecules (hydrogen bonds) the more likely it is that the solvent will dissolve in water
Which solvents are water-miscible?
- Acetone
- Ethanol
- Water
Which solvents are immiscible with water?
- DCM
- EtOAc
- Hexane
- MTBE
- Toluene
Which solvents have intermediate boiling points?
- Hexane
- EtOAc
- Ethanol
Which organic solvents are more dense than water?
- DCM
Which solvents have low boiling points?
- Acetone
- DCM
- MTBE
Which solvents have high boiling points?
- Water
- Toluene
If atmospheric pressure is increased, how is boiling point affected?
Boiling point is increased.
The degree of solubility of organic compounds is typically a function of solvent ___________.
volume
What is the dielectric constant?
- a physical measurement of how a substance interacts with an electric field
- can be used to compare the polarity of different solvents
- a measure of a solvent’s insulating ability/ability to balance part of the solute’s charge when it comes to the interaction with a molecule’s formal or partial charge
What is a hydrogen bond donor?
A hydrogen attached to an electronegative atom
- Ex. OH, NH, SH
What is a hydrogen bond acceptor
- each electronegative atom attached to a H
How do you count hydrogen bond donors?
- count the Hydrogens on electronegative atoms
How do you count hydrogen bond acceptors?
- count the number of non-bonded/lone pairs on the electronegative atoms
- this includes, ethers, esters, carbonyls
- do not count amide nitrogens, unless they are primary amides or anilines
- LPs in sp2 orbitals are almost always HBAs
