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.)

180 mg

Explanation:

For a first-order reaction, we can calculate the amount of aspirine (A) at a certain time (t) using the following expression.

where,

k: rate constant

A₀: initial amount

If we know the half-life () we can calculate the rate constant.

When t = 4 h and A₀ = 400 mg, A is:

a. the law of proportion states the combination of 2 atoms in a specific ratio to produce multiple compounds such as the given statement of question ‘1st compound contains 88.8 % cu ’ indicates 88.8 g of cu is present along with 11.2 g oxygen in 100 g of compound whereas the statement ‘2st compound contains 79.9 % cu ’ indicates 79.9 g of cu is present along with 20.1 g oxygen in 100 g of compound

1st compound contains 88.8 g cu

for cu

m = 63 g /mol

atomic % = 88.8 /63 = 1.42

for o

m = 16 g /mol

atomic % = 11.2 /16 = 0.7

b. the emperical formula of 1st compound is

cu1.4o0.7

cu2o