5. The gas-phase decomposition of ethyl iodide to give ethylene and hydrogen iodide is a first-order reaction. C2H5I  C2H4 + HI At 600 K, the value of k is 1.60 × 10– 5 s– 1. When the temperature is raised to 700 K, the value of k increases to 6.36 × 10– 3 s– 1. What is the activation energy for this reaction?

The activation energy for the reaction is 209 kJ

Explanation:

According to the Arrhenius equation,

or,

where,

= rate constant at =

= rate constant at =

= activation energy for the reaction = ?

R = gas constant = 8.314 J/mole.K

= initial temperature =

= final temperature =

Now put all the given values in this formula, we get :

Therefore, the activation energy for the reaction is 209 kJ

when the volume of gas is   changed from   717.73 ml   to 852 ml   the temperature will   change   from 315   c to 452   c

    calculation

this is calculated using the charles law formula

that is,   v1/t1 = v2/t2

          v1=?

        t1 = 315 c   into   kelvin = 315 +273 = 588 k

        v2 = 852   ml

        t2 = 425c + 273 =698 k

make v1   the subject of the formula ( by   multiplying both side by t1)

  v1=( v2 xt1) / t2

v1= (852 ml   x 588 k)/ 698 k= 717.73 ml