Did a Caffeine Extraction and Sublimation

Did a Caffeine Extraction and Sublimation (Experiment 4A for Chem 6AL). My TA provided the equation (Final Mass solute)h20 divided by (initial mass solute)h20 as equal to (V2/V2 V1xK)^n. She indicated that the final mass solute section was Y and the initial mass solute was x and that x-y=theoretical mass to use to calculate % yield. V1 is the organic DCM of 10 mL for each of the 4 extractions (n). V2 was 42 mL of the aqueous solution. K the partition coefficient is 1.8 for DCM/water. How does the equation correlate? Is it the ratio of the 2 equations is the same? I am not sure what to use as the final mass solute (was it our crude solid was .03 g and pure caffeine was .027 g?) and the initial I assumed to be the 55 mg caffeine per tea bag (used 2 bags so 110 mg). However the way that my TA said it that was not what we were supposed to do. My question is what is the theoretical mass that I should use to calculate the % yield? Also how would I calculate the efficiency of the extraction/sublimation.

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