As with any drug, aspirin (acetylsalicylic acid) must remain in the bloodstream long enough to be effective. assume that the removal of aspirin from the bloodstream into the urine is a first-order reaction, with a half-life of about 3 hours. the instructions on an aspirin bottle say to take 1 or 2 tablets every 4 hours. if a person takes 1 aspirin tablet, how much aspirin remains in the bloodstream when it is time for the second dose? (a standard tablet contains 400. mg of aspirin.)

Which position represents spring in the southern hemisphere? a) b) c) d)

A3.37-mg sample of protein was chemically digested to convert its nitrogen into ammonia and then diluted to 100.0 ml. then 10.0 ml of this solution was placed in a 50-ml volumetric flask and treated with 5 ml of phenol solution plus 2 ml of sodium hypochlorite solution. the sample was diluted to 50.0 ml, and the absorbance at 625 nm was measured in a 1.00-cm cuvette and found to be 0.486. for reference, a standard solution was prepared from 10.0 mg of nh4cl (molar mass = 53.49 grams/mole) dissolved in 1.00 l of water. then 10.0 ml of this standard was placed in a 50-ml volumetric flask, treated in the same manner as the unknown, and the absorbance found to be 0.323. finally, a reagent blank was prepared using distilled water in place of unknown, it was treated in the same manner as the unknown, and the absorbance found to be 0.076. calculate the weight percent of nitrogen in the protein.

What woukd most likely be the transmittance at a 0.70 m solution of solute a? a) 7.6%b) 1.1%c)4.0%d)4.6%