Stephs test

Question 1

where you would dispose of The top tea layer from the caffeine extraction lab?

Answer 1

Aqueous waste

Question 2

where you would dispose of A solution of 1-octanol in hexanes

Answer 2

Non-halogenated waste

Question 3

Are Water and dichloromethane miscible or immisicible?

Answer 3

Immiscible

Question 4

what makes the perfect solvent for recrystallization?

Answer 4

We want a solvent which its solubility changes the most as temperature changes. This allows for a lot of solute to dissolve at high T and very little solute to dissolve at low T – the perfect combination for
recrystallization.

Question 5

During the TLC lab we used a mixture of DCM (80%) and hexanes (20%). Imagine upon
visualizing the spots you notice that they are not very separated and have a very high Rf
(near 1). How would you change the solvent mixture to fix this problem?

Answer 5

Switch to a more non-polar solvent mixture. Maybe 60% DCM

and 40% hexanes.

Question 6

Give two methods that could be used to determine the purity of your recrystallized product
AND explain how the results of these tests would prove that your sample was pure

Answer 6

1 – test the MP of your product and compare the observed MP to the literature value

2 – Run a TLC plate and test the impure product and compare that to your recrystallized sample. If your sample only shows one spot, that indicates your product is pure