Lab 5: Base Extraction

Question 1

Formula for fraction of solute remaining in orginal solvent

Answer 1

Fa= (Vo/ KVx + Vo) ^n

Vo= volume orginal solvent
GC= volume extracting solvent 
N= number extractions
K= partition coefficient

Question 2

For effective acid base extraction

Answer 2

Keq > 1.0

Pkeq = pKa (acid left) - pKa (acid on right)

Keq = 10^ -( pkeq)

Question 3

Requirements for extracting solvent

Answer 3

1. Does not react irreversibly with the solute being extracted
2. Immiscible with orginal solvent
3. Selectively removes desired compounds
4. Easily separated from solute

Question 4

Requirements for recrystallization solvent

Answer 4

1. Not reactive with desired products
2. Desired product is completely soluble at elevated temperatures but only slightly soluble at room temperatures
3. Undesired components are highly soluble at all temperatures.
4. Easily removed from crystalline product by filtration and evaporation.

Question 5

Three groups that are commonly ionized

Answer 5

Carboxylic acid, phenol, ammonium cation/ amine with OH-, OH-, and water