400cm3 beaker full of water A sheet of paper with white spot on it
2 boiling tubes 2 statives with clamping equipment
2 20cm3 labelled measuring cylinders 100cm3 of 0.50M HCl
100 cm3 0.10M sodium thiosulphate 2 200cm3 beakers
Thermometer Timer Bunsen burner Labels(4) Matches
1. Put the tubes into the beaker so that they are half - immersed and connect the Bunsen burner.
2. Put the paper with the dot behind beaker A.
3. Add acid to B and thiosulphate to A (label cylinders and beakers).
4. Wait a bit when the temperature of water = temperature of reactants.
5. Add acid quickly to thiosulphate, start timer, stir with thermometer and record temp. =
6. Measure the time for the dark spot to disappear completely time =
7. Repeat first 6 in different temperatures given below.
Temperature /C |
Temperature/ K |
1/T (x1000 K-1) |
Time /s |
1/t (rate) /
x1000s-1 |
ln(rate) |
(in the firs exp.) |
+273 |
|
|
|
|
20 |
293 |
3.41 |
|
|
|
25 |
298 |
3.36 |
|
|
|
30 |
303 |
3.3 |
|
|
|
40 |
313 |
3.19 |
|
|
|
50 |
323 |
3.1 |
|
|
|
60 |
333 |
3 |
|
|
|
rate =. Activation energy is a tangent of 1/T against ln(rate).