In some cases, it is found that a large number of colliding molecules have energy more than thereshold value, yet the reaction is slow. Why?

In some cases, it is found that a large number of colliding molecules have energy more than threshold value, yet the reaction is slow. Why?

(a) The decomposition of A into products has a value of K as 4.5 xx 10^(3)s^(-1) " at "10^(@)C and energy of activation 60kJ "mol"^(-1) . At what temperature would K be 1.5 xx 10^(4) s^(-1) ? (b) (i) If half life period of a first order reaction is x and 3//4^(th) life period of the same reaction is y, how are x and y related to each other ? (ii) In some cases it is found that a large number of colliding molecules have energy more than threshold energy, yet the reaction is slow. Why?

(a) The decomposition of A into products has a value of K as 4.5 xx 10^(3)s^(-1) " at "10^(@)C and energy of activation 60kJ "mol"^(-1) . At what temperature would K be 1.5 xx 10^(4) s^(-1) ? (b) (i) If half life period of a first order reaction is x and 3//4^(th) life period of the same reaction is y, how are x and y related to each other ? (ii) In some cases it is found that a large number of colliding molecules have energy more than threshold energy, yet the reaction is slow. Why?

In some chemical reactions, it is found that a large number of colliding molecules have energy more than threshold energy value, yet the reactions are quite slow. Explain.