2206-008 Chemistry HL
Data collection – quantitative data
Concentration of potassium iodide solution, Mpotassium iodide / cm3
Time taken for “xâ€? to be obscured, t’ /s (Âą 0.01) Run 1
Run 2
Run 3
0.10
5.28
4.75
4.47
0.075
6.25
6.62
8.75
0.050
17.75
15.13
14.94
0.025
36.00
28.12
24.75
0.010
45.63
42.81
52.00
Table 2: Collected data
Data collection – qualitative data The colourless solution in conical flask “B� turns dark blue at the end of each run.
Data processing The average time taken for each potassium iodide solution concentration is calculated: Concentration of potassium iodide solution, Mpotassium iodide / cm3
Average time taken, t /s (Âą 0.01)
1
Rate of reaction, đ?‘Ą / s-1
0.10
5.28+4.75+4.47 3
= 4.83
1 4.83
= 0.207
0.075
5.28+4.75+4.47 3
= 7.21
1 7.21
= 0.139
= 15.94
1 15.94
= 0.063
0.050
6.25+6.62+8.75 3
0.025
36.00+28.12+24.75 3
= 29.61
1 29.61
= 0.034
0.010
45.63+42.81+52.00 3
= 46.81
1 46.81
= 0.021
Table 3: Calculation of the average time taken and rate of reaction
5