Solvent selection for crystallization

Question 1

Solvent selection for crystalization:
The CP (compound we wish to purify) must be ______ in solvent at room temperature and ____ just below the solvent’s bp.

Answer 1

Insoluble at room temperature

Soluble just below solvent Bp

Question 2

Solvent selection for crystalization :The bp of the solvent must be _____than the mp of the CP to avoid producing oil as opposed to crystals.

Answer 2

Lower

Question 3

Chair stability

Answer 3

chair most stable
hapf chair least stable

Question 4

sublimation

Answer 4

Solid to gas

Question 5

For a substance to change phase into a gas, its molecules must reach a vapor pressure equal to that of its ______

Answer 5

External air pressure

Question 6

Because a vacuum lowers the air pressure, the caffeine can reach this vapor pressure at a ______ _______and bypass the _______

Answer 6

Lower temp

Liquid phase

Question 7

One of the following is not a desirable property for the recrystallization solvent

Answer 7

High Bp

Question 8

The correct steps (in order) in the mechanism of ester hydrolysis

Answer 8

Addition of nucleophile – elimination of the LG – proton transfer