It has been found that DDT in the soil decomposes by a first-order reaction with a half-life of 12.0 years. How long would it take DDT in a soil sample to decompose from a concentration of 445 ppbm (parts per billion by mass) to 15 ppbm?

A flask contains a mixture of compounds A and B. Both compounds decompose by first-order kinetics. The half-lives are 73.00 min for A and 28.00 min for B. If the concentrations of A and B are equal initially, how long will it take for the concentration of A to be four times that of B?

How do you solve this?

Enrofloxacin is a drug used for dogs and cats to combat bacterial infections.A dog was given an intramuscular injection of enrofloxacin, and just after the injection, the initial concentration of the drug in the dog’s blood was 5.8Í10–6 M. If the enrofloxacin disappears in a first-order process with a half-life of 4.6 hours, how many hours will it take for the enrofloxacin concentration of drop to one-eighth (1/8th) of the initial concentration (i.e., 0.125[A]0)?

Calculate the half life, in minutes, for a second order reaction with an initial concentration of 0.45 M and a rate constant, k, of 0.017 M/s.

Can someone please help with question 3

A first order reaction has a half life 445.44 seconds. What is the rate constant in reciprocal seconds?

It has been found that DDT in the soil decomposes by a first-order reaction with a half-life of 12.0 years. How long would it take DDT in a soil sample to decompose from a concentration of 165 ppbm (parts per billion by mass) to 15 ppbm?

A reaction is found to be first-order with a rate constant of 0.0525 s–1. If the reaction initially began with 5.25 M reactant, how long (in s to the nearest whole number) will it take for 0.20 M reactant to be consumed?

A radioisotope of iodine, 13¹1, is used to study thyroid function. A patient is given a sample that is 1.70 × 10-4 M 1311. If the half-life is 8.04 days, what fraction of the radioactivity remains after 39.0 days? Radioactive decay is a first-order process.