hours k = ( ) hours Substitute the value of k in equation ( ) t . hours % log ( ) t 8hours x . % = t hours % Example (ii) The half life of a first order reaction x products is . x s at 500K .
W h a t percentage of x would be decomposed on heating at 500K for min. (e = . ) . Solution: Given t x = s To solve : when t= min, ] [ ] ?
x − We know that For a first order reaction, t k = k . x k s XII U7 kinetics - Jerald XII U7 kinetics - Jerald - - - - k = t ln [A ] [A] s x x s = ln [A ] [A] = ln [A ] [A] [A ] [A] = e [A ] [A] = ∴ - A % ] [ ] = × - A % [ ] = × - % = . % Example Show that in case of first order reaction, the time required for . % completion is nearly ten times the time required for half completion of the reaction.
Let ; [ ] . ) when t = t ; A - . % k t log [A ] [A] t k . .
% log t k . % log t k . % ( ) t k . % t x k .
% t t . % Evaluate yourself: ( ) In a first order