org chem lab quiz 1

Mp of impure benz acid

118.0- 123.0

Mp of pure benz acid

121.0- 122.0

Recrystallization

is the separation of a mixture of substances into pure

components on the basis of their solubilities.

hot gravity filtration

Used to remove insoluble(solids) and colored impurities

Charcoal ( activated carbon )

Added to remove colored impurities

Solvent conditions

dissolve when hot and precipitate when cold, either dissolves impurities of solute or doesn’t dissolve at all, should not react with solute, must be easily volatile.

Crystallization

Slow cooling, larger crystals

Precipitation

Fast and non selective cooling , smaller crystals

.

suction filteration

Hot g filteration

Caffeine chemical structure

Purine ring, alkaloids members (nitrogenous compound )

Cellulose

Water insoluble, not to be eaten

Tannins

Contains acidic properties which give color to tea

Caffeine

White color, water soluble

Emulsion

mixture of two immiscible solvents in which one solvent

dispersed in the other.

Na2CO3 (sodium carbonate)

Added to tannin which give us tannin salts and tannin salts are soluble in H20 but insoluble in dichloromethane

Na2SO4 (sodium sulfate)

Added to remove dichloromethane and to absorb water residues