Solveeit Logo
Login

Question

Question: In a first order reaction the concentration of reactant decreases from \(800mol/dm^{3}\) to \(50mol/...

In a first order reaction the concentration of reactant decreases from 800mol/dm3800mol/dm^{3} to 50mol/dm350mol/dm^{3}in 2×102sec⁡2 \times 10^{2}\sec. The rate constant of reaction in sec⁡−1\sec^{- 1}{} is

A

2×1042 \times 10^{4}

B

3.45×10−53.45 \times 10^{- 5}

C

1.386×10−21.386 \times 10^{- 2}

D

2×10−42 \times 10^{- 4}

Answer

1.386×10−21.386 \times 10^{- 2}

Explanation

Solution

k=2.303t 6mulog⁡10a(a−x)k = \frac{2.303}{t}\mspace{6mu}\log_{10}\frac{a}{(a - x)}; t=2×102sec⁡t = 2 \times 10^{2}\sec,

a=800mol/dm3a = 800mol/dm^{3}

(a−x)=50mol/dm3(a - x) = 50mol/dm^{3}

k=2.3032×102log⁡1080050=1.386×10−2sec⁡−1k = \frac{2.303}{2 \times 10^{2}}\log_{10}\frac{800}{50} = 1.386 \times 10^{- 2}\sec^{- 1}{}