1. Extraction Extraction is a general theory for the recovery of a substance from a mixture by bringing it into contact with a solvent which preferentially dissolves the desired material. In organic chemistry, the reaction product is frequently obtained as a solution in water along with other organic and inorganic byproducts.

2. Let’s get started To begin this lesson, click on the web address below and view the first 9 pages. http://www.slideshare.net/Atharsaeedi/extrac tion-theory http://www.slideshare.net/Atharsaeedi/extrac tion-theory Return to this powerpoint after viewing the first 9 pages.

3. Let’s do the math By definition, the distribution coefficient is: concentration in the organic layer concentration in the water layer Let us consider compound A: 10g of compound A will dissolve in 100ml ethyl ether (an organic compound) 2g of compound A will dissolve in 100ml of water Calculate the K D for compound A K D =

4. Determining the K D concentration in the organic layer = 10g/100ml concentration in the water layer 2g/100ml K D = 5 If you are given a solution of 1g of compound A dissolved in 100ml of water, how much could you extract if you did one extraction using 75ml of ethyl ether? K D =

5. Set up the problem Solve for X by cross multiplying two times. Go to the next page to see the value for X.

6. X = 0.556g This means that 0.556g of compound A has now moved to the ethyl ether layer. How much compound A remains in the water? 1g – 0.556g = 0.444g of compound A in the water.

7. Try another problem? 15g of compound J dissolves in 100ml of benzene. 5g of compound J dissolves in water. You are given a solution with 2g of compound J dissolved in 100ml of water. If you do one extraction with 50ml of benzene, how many grams of compound A can you extract from the water?

8. Solve for K D and 1 st extraction

9. In the experiment you will: dissolve caffeine in water. extract the caffeine with chloroform. do two extractions. The math for doing more than one extraction and why it is valuable is the enrichment for this section.