Calculate the percent caffeine by mass
Caffeine is a stimulant found in coffee and tea . A solution of caffeine in chloroform as a solvent has a concentration of 7.90×10-2 . Calculate the percent caffeine by mass.
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At room temperature (20), milk turns sour in about 65 hours. In a refrigerator at 3, milk can be stored three times as long before it sours. What is the activation energy of the reaction tht causes the souring of milk?
In a controlled greenhouse at 30.0ºC and 1.0 atm, a crop of seedling tomato plants was found to consume 380 L of carbon dioxide gas during photosynthesis.
Locate an article on another company that experienced similar difficulties with Mark to Market like AIG (American Insurance Group). Summarize the facts and provide a citation.
A dead alkaline battery is found to contain a compund of Mn and O. Its analysis gives 69.6% Mn and 30.4% O.
The absorbance of the new solution was 0.500. What is the concentration of Cu2+ in the sample? State any assumptions you might make and pay attention to significant figures.
What is the molarity of a solution made by dissolving 0.0815 grams of Na2SO4 in enough water to form exactly 750. mL of solution?
The pH of the resulting solution is 8.0. Then you add 40 mL of 1.0 M hydrochloric acid (HCl) to the solution. What is the new pH?
How is the solubility of manganese(II) sulfide affected by the addition of aqueous potassium hydroxide to the system?
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