Home >> Science & Nature >> Science

How to Calculate Percent Recovery in Acid Base Extraction

In organic chemistry labs, acid base extraction is a convenient way to separate components of a mixture. It relies on the principle that an organic acid or base generally becomes more water-soluble when you neutralize it to make a salt. Once you perform an extraction of this kind, you need to calculate a percent recovery to determine precisely how well you did. The data you need are the starting amount of each kind of compound present and the final amount you recovered.

Instructions

- 1
  Estimate how much of each compound was present originally. If you started with a sample composed roughly of one-third neutral compound, one-third organic base and one-third organic acid, you can take the starting sample mass and multiply it by 1/3 to get the starting mass of each. For example, if you started with 1 gram of material, multiply by 1/3 to get 1/3 gram of neutral compound, 1/3 gram of organic base and so forth.
- 2
  Divide the final amount of each type of compound by the starting amount. If you ended up with 1/10 gram of organic base, for example, and you started with 1/3 gram, you would divide 1/10 by 1/3 to get 3/10.
- 3
  Multiply your answer from the last step by 100 to convert it into a percent format. To continue the same example, 0.3 x 100 = 30 percent.
- 4
  Note that your percent recovery may be different for each type of compound. That's entirely normal, because an acid-base extraction is a multistep process. So depending on how careful you were with each step, you might have a better percent recovery for some of the compounds in the mixture than for others.

Science