For a first-order reaction, the half-life t_(1/2) is:
A0.693/k (independent of initial concentration)
BInversely proportional to [R]₀
CEqual to 1/k
D[R]₀/(2k)
Answer & Solution
Correct answer: A. 0.693/k (independent of initial concentration)
First-order **t_(1/2) = ln(2)/k = 0.693/k**. **Independent of initial concentration** — a defining feature of first-order reactions. (Zero-order t_(1/2) = [R]₀/(2k) — depends on initial concentration.)
Related questions
It is observed that for many reactions the rate constant nearly doubles for a rise in tempThe half-life for the radioactive decay of carbon-14 is 5730 years and decay is first ordeIn a pseudo first order reaction, [A]/mol L^-1 reads 0.31 at t = 30 s and 0.17 at t = 60 sIn collision theory, what is meant by the collision frequency (Z)?According to collision theory, in the modified rate expression Rate = P Z_AB e^(-Ea/RT), wHow does a catalyst increase the rate of a chemical reaction?The first order rate constant for decomposition of ethyl iodide is 1.60 x 10^-5 s^-1 at 60The rate constants of a reaction at 500 K and 700 K are 0.02 s^-1 and 0.07 s^-1 respective