12. Various methods are employed in order to remove the caffeine from coffee beans to make decaffeinated or "decaf" coffee. Some older methods used organic solvents like dichloromethane or chloroform. A solvent which is still sometimes used is water, but now a common method is extraction by carbon dioxide as a supercritical fluid. When using the latter method, water is used as a co-solvent. How would you expect adding the water to affect the amount of caffeine extracted?? water O=C=0 caffeine carbon dioxide 13. Many people use insecticides on their pets to kill and prevent fleas and ticks. Fipronil and methoprene are two common ingredients in flea and tick medications for pets. Fipronil is an insecticide, while methoprene and hydroprene are insect growth regulators. Which of these would be most soluble in water? Least? hydroprene NH2 methoprene fipronil