JEE Advanced levelOne or more correct optionsDifficulty 3 of 3ck098
For A+BP, rate =k[A][B] with k=0.30Lmol−1s−1. A run has [A]0=1.0×10−3molL−1 and [B]0=0.60molL−1. Take ln2=0.693 and treat [B] as constant. Select the correct statement(s).
AIf [A]0 is doubled, the half-life of A becomes 1.92s.
BThe pseudo first order rate constant is 0.18s−1.
CThe half-life of A is 3.85s.
DIf [B]0 is halved, the half-life of A becomes 7.70s.
Answer: B, C, D
With B in 600-fold excess, k′=k[B]0=0.18s−1 and t1/2=0.693/k′=3.85s. A pseudo first order half-life does not depend on [A]0, so doubling it changes nothing. Halving [B]0 halves k′ and doubles the half-life to 7.70 s.