Organic Separation Techniques (5/15)

Question 1

Extraction

Answer 1

Separates liquid mixtures by partitioning compounds between two liquid phases organic and aqueous phase (polar)

Question 2

Separating solutes

Answer 2

solutes with similar traits will separate based on density

Can also give one of the molecules a charge, if possible, to put it into the aqueous phase

Question 3

Determining if a molecular will go to organic layer (is nonpolar)

Answer 3

Molecules with one polar group for every 5 carbons is non-polar

Question 4

Extracting using acid-base properties

Answer 4

adding a strong acid to an organic phase will allow it to go to aqueous
or adding a base to an acid so it becomes negative and goes to aqueous

Question 5

If we have two acids

Answer 5

can be separated by adding a weak base and it will deprotonate the stronger acid so it can go to aqueous layer

Question 6

Volatile substances

Answer 6

easily transitions from liquid to the gas phase

Question 7

Distillation

Answer 7

process to separate liquids by boiling point, volatility, and vapor pressure

Question 8

Vapor pressure

Answer 8

pressure exerted by molecules entering gas phase
pressure increases as temperature increases
pressure increases if more volatile (lower boiling point, more easily boiled)

Question 9

Volatility

Answer 9

polar= hydrogen bonding and have a higher boiling point 
size= larger means higher boiling point

Question 10

Simple distillation

Answer 10

separates liquids with boiling points 25 C apart or more (very different boiling points)

Question 11

Fractional distillation

Answer 11

can separate liquids with closer boiling points

Question 12

How does fractional distillation separate?

Answer 12

increases vertical distance vapor travels

allows liquids to re-condense or re-vaporize

Question 13

Unsure of being able to reach high boiling point

Answer 13

lower pressure with vacuum distillation so liquids boil at a lower temperature

Question 14

Polar compounds and vapor pressure

Answer 14

have a lower vapor pressure

Question 15

TLC

Answer 15

usually has a nonpolar mobile phase so nonpolar travels further than polar

Question 16

Retention factor

Answer 16

Rf value

Question 17

Column chromatography

Answer 17

Separates components of a mixture based on size

large goes first

Question 18

Ion exchange

Answer 18

electrostatic interactions
Cation: negative charge stationary phase (traps positive molecules)
Anion: positive charge stationary phase (traps negative charge molecules)

Question 19

Affinity

Answer 19

ligands designed to bind specific compound sticks

Question 20

Gas liquid chromatography

Answer 20

gas: stationary phase

Question 21

High performance liquid chromatography

Answer 21

uses extremely high pressures
nonpolar moves faster
reverse phase: polar moves faster because mobile phase is polar

Question 22

Recrystallization

Answer 22

making more pure

soluble at high temperature and insoluble at lower temperatures

Question 23

Nucleation

Answer 23

a tiny crystal initiates crystallization process. if slow, scratch side of glass