The activation energy for the reactio `2HI_((g))to H_(2(g))+I_(2(g))at 581` K is `209. 5kJ//mol.` Calculte the fraction of molecules having energy equal to or grater than activation energy. `[R=8.31 JK^(-1)mol ^(-1)]`

Explanation

Fraction of molecules [x] having energy equal to or more than activation energy may be calculated as follows :
`x=n//N=e^(-E_(a)//RT)`
`In x= (-E_(a))/(RT)or log x=(-E_(a))/(2.303RT)`
or `log x=-(209.5xx10^(3)J mol ^(-1))/(2.303 xx[8.314JK ^(-1) ]xx581 K)=-18.8323`
x = Antilog `[-18.8324]=` Antilog `bar(19).1677=1.471xx10^(-19)`
Fraction of molecules `=1.471xx10^(-19)`