caffiene extraction discussion

Discussion:

Impure caffeine was extracted from the instant coffee by separation and evaporation. The amount of impure caffeine in 4.0045g of instant coffee was found to be 64.5mg with a yield of 1.6%. The yield is higher than the overall class average yield. This shows that there is a source of error. With the yield being higher, it is possible that the product did not have applicable time to dry and could still have been wet, which would make it heavier.
Through a new technique called sublimation 11.4mg of pure caffeine was extracted from 4.0045g of coffee with a yield of 0.28%. This yield is very low, which shows that there is a lot of impurities present in impure caffeine.
In comparison, Black tea has a lot less caffeine than black coffee with an average yield of 0.199 % for impure caffeine in tea and a yield of 0.948 % for impure caffeine in coffee. This shows that there is almost 4 times as much impure caffeine in coffee than there is in tea. The average yield of pure caffeine in tea was 0.113% with coffee having an average yield of 0.330%.
The average 16 ounce cup of coffee from Starbucks is known to have 330mg of caffeine, in our experiment enough coffee was used to make a 16 ounce cup and only recovered an average of 40.19 mg was recovered. The average 16 ounce cup of tea from Starbucks is known to have 135mg of caffeine and the average recovered caffeine from the experiment was only 6.95mg.
Thirteen other groups from four different sections also extracted caffeine from instant coffee. The average pure caffeine yield was 0.330% with a standard deviation of 0.179. This yield is slightly higher than the yield of this report because of the error that occurred during the experiment. A small amount of coffee from the first extraction was stuck in the nozzle of the separatory funnel so it was removed with a pipet and then decanted. This resulted in a loss of product. The average impure caffeine yield was found to be .948% with a standard deviation of 0.659%. This is much lower than the yield discussed in this report. This could be due to insufficient drying since the amount of pure caffeine is smaller than the average, and impure is higher. The product could still be saturated. Overall, the experimental yields are very close to the average yields of the other groups.

Conclusion:
Caffeine was successfully extracted from the Maxwell house instant coffee. The final product of the impure caffeine was a yellow solid-powdery substance with a 1.6% yield and The final product of pure caffeine was a white solid- powdery substance, with only a slight shade of yellow in it and a yield of 0.28%.