Organic Chemistry Lab E1 Flashcards
What is the purpose of recrystallization?
Purifying solid compound
Example sentence: Recrystallization is commonly used in chemistry labs to obtain pure crystals from impure samples.
purpose of increasing temperature
To dissolve impure solids in solvents
Reason for slowly cooling solution
Doing it slowly makes it one large crystal and makes less impurities
Criteria for solvent in recrystalization
- soluble in hot/ insoluble in cold
- impurities insoluble in all temps
- solvent should not react with substances that you’re purifying
- solvents boiling point low enough to be removed from crystals
Purpose of liquid liquid extraction
Insoluble liquids/ non-polar and polar
Choosing solvents
You want the two liquids to be immiscible
Reason for pH change
Manipulate the equilibrium/ + charge will dissolve better with acids and - charge with bases
Reasons that two layers form
The use of two liquids that are immiscible
Reason to take melting points of products
To make sure you have organic products
Role of magnesium sulfate
To remove any residual water
Fraction distillation vs simple distillation
Frac dist uses fractional column/ tells the boiling point of different compounds
Role of beads in column
Allows the water to move up the fractional column
Reason for half filling distillation flask
It has to have enough head space
Role of boiling chips
Prevents bumping which is a way a liquid can heat up to fast and cause a dangerous work environment
Interpreting graph
Graph shows area where solutions temperature raised and dropped. The drop shows the boiling point of a compound
Role of water flowing in the condensing column
Allows vapor to be cooled and condensed
Purpose of steam distillation
Steam distillation is for heat sensitive organic compounds
Purpose of steam distillation
Steam distillation is for heat sensitive organic compounds
Purpose of the bromine test
The bromine test shows you correctly isolated the limonene
