The rate constant for the first order decompositon of {\H}_2 {\O}_2 is given by the following equation : \log k=14.2-\frac{1.0 \times 10^4}{ {\T}} {\K} \text{; } Calculate {\E}_a for this reaction and rate constant k if its half-life period be 200 minutes. (Given : {\R}=8.314 {\J} {\K}^{-1} {\mol}^{-1} )

CBSE Class 12 Chemistry 2016 Delhi Set 1 Solved Paper

Question : 13 of 26

Marks: +1, -0

The rate constant for the first order decompositon of

{\H}_2 {\O}_2

is given by the following equation :

\log k=14.2-\;{1.0 × 10^4}/{ {\T}} {\K} \;\text "; "\;

Calculate

{\E}_a

for this reaction and rate constant

k

if its half-life period be 200 minutes.
(Given :

{\R}=8.314 {\J} {\K}^{-1} {\mol}^{-1}

)

Solution:

\log k=\;{\log {\A}- {\E}_a}/{2.303 {\RT}}\;

\;{ {\E}_a}/{2.303 {\RT}}\;=\;{1.0 × 10^4 {\K}}/{ {\T}}

{\E}_{ {\a}}\;=1.0 × 10^4 × 2.303 × 8.314

\;=191471.4 {\J} \/ {\mol}

t_{\;{1}/{2}}\;=\;{0.693}/{k}

k\;=\;{0.693}/{200} {\min}

\;=0.0034 {\min}^{-1}

Go to Question:

Prev Question

Next Question