• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

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

Extracts from this document...


I. Aim: To determine the activation energy of the reaction between bromide ion and bromate(V) ion in acid solution. II. Theory: The progress of the reaction may be followed by adding a fixed amount of phenol together with some methyl red indicator. The bromine produced during the reaction reacts very rapidly with phenol. Once all the phenol is consumed, any further bromine bleaches the indicator immediately. So, the time for the reaction to proceed to a given point may be determined. Measuring the time, t, for the reaction to proceed to the same (small) extent at different temperatures. Then, a graph of ln against should be a straight line of gradient (using the Arrhenius equation). Therefore, we can determine he activation energy of the reaction between bromide ion and bromate(V) ion in acid solution. Equation for the reaction between phenol and bromine: C6H5OH (aq) + 3Br2 (aq)C6H2(OH)Br3 (aq) + 3 HBr (aq) (phenol) (2,4,6-tribromophenol) III. Chemicals: Quantity Solution A (0.083M with respect to KBr and 0.017M with respect to KBrO3) 60 cm3 0.5 M H2SO4 30 cm3 0.01 M phenol solution 60 cm3 Methyl red indicator Several drops I. ...read more.


[1] ? All concentration terms have been kept constant ? Rate only varies as k (rate constant) ? Rate is directly proportional to 1/t & varies as k in the rate equation ? We can substitute k by 1/t in [1]: ln (1/t) = ln A - Ea�(RT), which is the equation of the previous graph From the graph, the slope is -6.7659 ? -Ea = (- 6.7659) (R) Ea = (-6.7659) (8.3) = 56.16 Jmol-1 VII. Discussion: 1. Why does the reaction not start until the contents of the boiling tubes are mixed ? There are three reactants in the reaction, i.e. Br-(aq), BrO3-(aq) and H+(aq) ions. The three reactants are put separately in the two boiling tubes. If the contents of the boiling tubes are not mixed, the three reactants are not mixed and the reaction will not start. 2. What is the function of phenol in this experiment? The reason for adding a small amount of phenol at the start is that it will react with the bromine formed early in the reaction. ...read more.


Conversely, lowering T makeslarger, then k will decrease and the reaction proceed slower. Similarly, if Ea is low,will be small. Then, k will be large and the reaction will be fast. If Ea is high, will be large. Then, k will be small and the reaction will be slow. 8. Explain the fact that the reaction with low activation energy proceeds faster. If the activation energy is low, more collisions between reactant particles would have collision energies higher than activation energy (the minimum energy for the reaction occurs). In other words, there are more collisions between reactant particles are effective. 9. Errors -Temperature is recorded when the solution bleaches. However, the reaction temperature would vary throughout the reaction period, especially if the reaction starts before the temperatures of the solutions become steady. Therefore, if the temperature is lower, we should put the boiling tube in the water bath; if the temperature is higher, we should get out the boiling tube from the water bath. -If the reaction may not be stirred well, the reaction mixture may not be homogenous, and this will lead to a greater time reading. VIII. Conclusion: The activation energy of the reaction between bromide ion and bromate(V) ion in acid solution is 56.16 Jmol-1 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Inorganic Chemistry section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Inorganic Chemistry essays

  1. Peer reviewed

    Determining the concentration of acid in a given solution

    5 star(s)

    I am using titres of approximately 30cm3. I will need some sodium carbonate solution to rinse the burette, solution to do a rough titration, and I will want about 5 titres worth to get 3 accurate titres so I will need (7x30)= approximately 210cm3 of sodium carbonate solution.

  2. Peer reviewed

    Deducing the quantity of acid in a solution

    5 star(s)

    * Methyl orange Methyl orange is toxic if swallowed or inhaled. In solutions, like the one we are preparing, the hazard is very low (because they are less than 1% by mass). Also, methyl orange can be highly flammable. In order to be precautious and preventive, we are going to use eye protection (goggles)

  1. effects Concentration and Temperature on the Rate of Reaction

    This theory suggests that reactions occur when the particles of reactants collide, provided that they collide with a certain minimum kinetic energy. Concentration of Reactants: If the concentration of the reactant molecules is increased there will be more molecules.

  2. Determining an Equilibrium Constant

    /g 106.11 75.15 72.79 67.62 71.75 Mass of HCl(aq) added /g 5.10 5.16 5.08 5.10 5.18 (6) Mass of water in HCl(aq) /g 4.7208 4.7808 4.7008 4.7208 4.8008 Mass of bottle after adding CH3COOCH2CH3(l) /g - - 77.13 71.05 73.41 Mass of CH3COOCH2CH3(l) added /g - - 4.34 3.43 1.66 (7)

  1. Bleaching experiment. Estimation of available chlorine in commercial bleaching solution.

    After the addition of starch, the mixture turns deep blue. Hence if the end point was only detected by the color of iodine in iodide (the change in color 'brown-->yellow-->colorless', there would be a large percentage error, provided that this kind of end point is very difficult to observe.

  2. Determination of the formula of complex ion

    ions can be found, by considering the mole ratio between them, the formula of Nickel-EDTA complex can be obtained. (d) Results: Final burette reading 25.7 32.0 26.5 Initial burette reading 0.4 7.4 1.7 Volume of EDTA 25.3 24.6 24.8 Average volume of 0.1M EDTA used = (25.3+24.6+24.8)

  1. Aim To study the effect of concentration of iodide ion ...

    1 The theory also states that effective collision can be affected by the concentration of reactants and temperature. In this experiment, the concentration factor is being studied. In terms of the iodine clock reaction, the concentration of iodide ions would, according to the Collision Theory, affect the rate of conversion of iodide to iodine.

  2. Finding Out how much Acid there is in a Solution

    * Dropping pipette * Clamp and clamp stand * White tile This is a list of all the chemicals I will need for my investigation: * Sulphuric acid (H2SO4 (aq)), concentration unknown * Sodium carbonate solid (Na2CO3 (s)), mass 2.65g * Deionised water * Methyl orange indicator Risk Assessment4 I

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work