Sample pre-lab quiz for Extraction experiment.

Besides the types of questions below, questions on handling of wastes and on lab etiquette will be included on all prelab quizzes.

1) The distribution (or partition) coefficient is:

1. the temperature at which a compound precipitates out of a solution
2. the ratio of the vapor pressure of a liquid and atmospheric pressure
3. the ratio of the amount of a compound which is a liquid and a solid at a particular temperature
4. the ratio of the concentrations of a solute in two solvents at a particular temperature

2) Under neutral conditions, a carboxylic acid is soluble in:

1. the aqueous phase
2. the organic phase

3) Consider the following table:

solvent	density (g/mL)	bp (°C)	comments
diethyl ether	0.7	35	highly flammable
ligroin	0.7	60	flammable
benzene	0.9	80	flammable, carcinogenic
toluene	0.9	111	flammable
methylene chloride	1.3	41	toxic
chloroform	1.5	61	toxic

When mixed with water, toluene would be on:

1. top
2. bottom

4) In the extraction experiment, vacuum filtration is used:

1. to remove drying agent
2. to isolate crude benzoic acid
3. to isolate crude phenanthrene
4. both b and c

5) In an extraction procedure, it is advisable to:

1. throw away all layers as soon as you have extracted them
2. save all layers until an experiment is complete
3. put the aqueous layer down the drain
4. put the organic layer in the aqueous waste

6) Which of the following compounds is an amine?

Answers.