The rate constant of a first order reaction at 27° C is 10-3 min -1. The rate constant (in min -1 ) at 17° C for this reaction?

Question

The rate constant of a first order reaction at 27° C is 10-3 min -1. The rate constant (in min -1 ) at 17° C for this reaction? (A) 10-3 (B) 5 × 10-4 (C) 2 × 10-3 (D) 102

Tardigrade Admin · Accepted Answer

Temperature Coefficient =(Kt+10/Kt) 2=(10-3/Kt) ⇒ Kt=(10-3/2)=(10-4 × 10/2) Kt=5 × 10-4

Q. The rate constant of a first order reaction at $2 7^{\circ} C$ is $1 0^{- 3} min^{- 1}$ . The rate constant (in $min^{- 1}$ ) at $1 7^{\circ} C$ for this reaction?

$1 0^{- 3}$

$5 \times 1 0^{- 4}$

$2 \times 1 0^{- 3}$

$1 0^{2}$

Temperature Coefficient $= \frac{K _{t} + 10}{K _{t}}$

$2 = \frac{1 0 ^{- 3}}{K _{t}} \Rightarrow K_{t} = \frac{1 0 ^{- 3}}{2} = \frac{1 0 ^{- 4} \times 10}{2}$

$K_{t} = 5 \times 1 0^{- 4}$

Q. The rate constant of a first order reaction at 27∘C is 10−3min−1. The rate constant (in min−1 ) at 17∘C for this reaction?

10−3

5×10−4

2×10−3

102