Experiment 10F(Chemistry TAS - Lab Report) - To determine the activation energy of the reaction between bromate ion and bromate(V) ion in acid solution

Authors Avatar

Experiment 10          Chemistry TAS           Lab Report (short)

14thFebruary, 2006

Name: Shek Pok Man, Dominic

Class: 6B (24)

Objective:

To determine the activation energy of the reaction between bromate ion and bromate(V) ion in acid solution.

Discussion

  1. 3Br2(aq) + C6H5OH (aq)  C6H5Br3OH(s) +3H+(aq) + 3Br-(aq)
  2. Methyl red was used because the solutions are colourless, the end point cannot be determined. However, using methyl red as indicator to give some color to the solution, at the end point the solution was bleached from red to colorless.
  3. No, as the rate of reaction increase directly proportional to the temperature, at the temperature=80oC, the rate is so fast that tme interval connot be measured.
  4. It is because the time noted is the time when the solution has just been decolourised, therefore, how far the reaction has proceeded is not a factor.
  5. From Arrhenius equation, we have k = Ae-Ea/RT, where A is Arrhenius constant.

    a) Yes, as all concentration terms have been kept constant. Therefore, the rate only varies as k, and the rate is directly proportional to 1/t & varies as k in the rate equation. We can substitute k by 1/t.


    b) By taking natural logarithm of k = Ae
    -Ea/RT, we have:
    ln k = (- E
    a/RT)+ ln A

    C) Results:
Join now!


In(1/t) VS against 1/T


By the equation: ln (1/t) = (- E
a/R)(1/T)+ ln A
∴slope of the graph = - E
a/R
(-5165.6)(8.31) = - E
a

           Ea = 42926kJmol-1

  1. Temperature affects the rate of reaction as the kinetic energy of molecules increase when temperature increase, thus, increasing the collision frequency which affects the rate of reaction. The higher the energy, the higher chance to overcome the activation energy barrier.
  2. Clock method means to follow a reaction by measuring the time taken to reach a predetermined stage. 
    In this task, we followed the reaction in ...

This is a preview of the whole essay