yveswang1998 發問時間: 科學化學 · 1 0 年前

Reaction Mechanism

please help me with these Qs on reaction mechanism. Thanks?

Please show me step by step of the Q 1 and explain the reason on Q 2, I will really appreciate it if you did, Thanks!!!

The activation energy of a certain uncatalyzed reaction is 64 kJ/mol. In the presence of a catalyst the activation energy if 55 kJ/mol. How many times faster is the catalyzed than the uncatalyzed reaction at 673 Kelvin?

A reaction mechanism usually is:

A. the same as the balanced chemical equation.

B. restricted to only one possible explanation.

C. obvious if the reaction order is known.

D. difficult to prove

E. Obvious if the activation energy is known.

1 個解答

  • 1 0 年前

    1.From the Arrhenius equation

    we can get the relationship between reaction rate constant and activation energy

    K catalized / K uncatal

    = [ A * exp(-55000/8.314*673)] / [A * exp(-64000/8.314*673)]

    = 4.995

    so we can get the rate of catalzed one is about five times faster than the uncatalyzed

    2. Ans:D

    the real reaction mechanishms contains some intermidiate which we can not get easyily

    A.the balanced equation just shows the final pieces after the reaction

    B.one reaction could has many way to form the product, so there will be many reaction mech. to present the same one reaction

    C.we can't get the information of intermidiate from reaction order

    E.different intermidiates could have the same activation energy, so we still can't get the exact information of intermidiate

    參考資料: ME
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