객관식Decomposition of a certain substance Y at 45°C was found to be zero order. What is the half-life of substance Y if it took 15.5 minutes to decompose 67% of this substance? [Y]0 = 0.25 M.1888views8rank6comments
객관식For a first-order reaction, what percentage of the reactant has been consumed after one half-life has elapsed?138views
객관식In a first-order reaction, what fraction of the original reactant has been consumed after 4 half-lives?73views
객관식If a sample initially contains 1.0 × 10^{12} atoms of the cadmium isotope 109Cd, which has a half-life of 462 days, approximately how many atoms of 109Cd will remain after 924 days?100views
객관식Which of the following is the correct formula for calculating the age of a meteorite using half-life?121views
객관식A radioactive isotope decays such that after 24 hours, only 25% of the original sample remains. What is the half-life of this isotope?119views
객관식Which of the following best describes the possible range of half-lives for radioactive isotopes?101views
객관식If the initial concentration of NO2(g) is 0.050 M, what is the half-life of the reaction at 300°C given that the rate constant k is 0.54 M⁻¹s⁻¹?627views
객관식After 5 half-lives have passed for 87Rb, what percentage of daughter isotopes would be present?85views