NEET Chemistry Chemical Kinetics Questions Solved


The first order rate constant for a certain reaction increases from 1.667×10-6s-1at 727°C to 1.667×10-4s-1at 1571°C The rate constant at 1150o C, assuming constancy of activation energy over the given temperature range is

(A) 3.911 × 10-5 s-1                               (B)1.139 × 10-5 s-1

(C) 3.318 × 10-5 s-1                               (D) 1.193 × 10-5 s-1

(C) 2.303 log1.667×10-41.667×10-6=-EaR11844-110002.303 ×2=EaR×8441844×1000      .....1EaR=4.606×1844×10008442.303  log K1.667×10-6=EaR×1423-10001423×1000EaR×4231423×1000                 .....2

Dividing equation (2) by equation (1)

logK1.667×10-62=4231423×1000×1844×1000844log K1.667×10-6=2×423×18441423×844=1.299K=19.9×1.667×10-6=3.318×10-5s-1

Difficulty Level:

  • 18%
  • 30%
  • 42%
  • 12%