Caffeine is a bitter stimulant drug and is found in varying quantities in seeds, leaves, and so on. its formula is c8h10n4o2. match the number of moles of each element found in the specified number of moles of caffeine.

Achemistry student weighs out 0.306 g of citric acid (h3c6h5o7), a triprotic acid, into a 250 ml volumetric flask and dilutes to the mark with distilled water. he plans to titrate the acid with 0.1000 m naoh solution. calculate the volume of naoh solution the student will need to add to reach the final equivalence point. be sure your answer has the correct number of significant digits.

About 3% of the water on earth is freshest. only about 40% of that freshwater is available for human use. why is so much freshwater unavailable for human use?

Why do the strengths of london (dispersion) forces generally increase with increasing molecular size? choose one: a. heavier atoms have stronger attractions for each other than lighter atoms. b. dispersion forces are all equal in magnitude; there is no size dependence. c. dispersion forces arise from the attraction between the nuclei of atoms, and larger molecules have larger nuclei. d. dispersion forces arise from dipoles caused by the electron distribution being distorted. larger molecules have more electrons and, therefore, more distortions and a bigger force. e. dispersion forces depend on distance. larger molecules are farther apart and so the forces are smaller.