2019 Year 12 IB Extended Essays

D ATA C OLLECTION R AW D ATA Ring number was deduced from the fifth (5 th ) ring as the distance variation at the upper end of the test tube was too difficult to definitively distinguish. Although the electronic balance had an accuracy of four decimal places, the mass of cobalt (II) chloride was given an uncertainty of ± 0.01g to account for lost mass in the transfer between the weighing dish and the test tubes, as residue was noticed the dish T ABLE 1: T ABLE SHOWING RESULTS OF TRIAL 1 Mass of Cobalt (II) Distance of ring from gel surface of nth ring. Measured in cm ± 1mm

Number of rings formed

Chloride ± 0.01 g

Ring Number

5

6

7

8

9

10

11

12

13

2.50 3.00 3.50 4.00 4.50

18 23 25 25 20

45 30 23 22 13

46 31 24 23 14

47 32 25 24 15

48 33 26 25 16

50 34 27 26 18

51 35 28 29 19

52 36 30 30 20

54 39 31 32 21

55 40 32 34 22

T ABLE 2: T ABLE SHOWING RESULTS OF TRIAL 2 Mass of Cobalt (II)

Numb er of rings formed

Distance of ring from gel surface of nth ring. Measured in cm ± 1mm

Chloride ± 0.01 g

Ring Number

5

6

7

8

9

10

11

12

13

2.50 3.00 3.50 4.00 4.50

16 24 27 24 20

43 32 24 24 11

44 33 25 25 12

45 34 26 26 13

46 35 27 27 14

47 36 28 28 15

48 37 29 30 17

49 39 30 32 18

50 40 31 33 19

52 41 32 34 20

T ABLE 3: T ABLE SHOWING RESULTS OF TRIAL 3 Mass of Cobalt (II)

Number of rings formed

Distance of ring from gel surface of nth ring. Measured in cm ± 1mm

Chloride ± 0.01 g

Ring Number

5

6

7

8

9

10

11

12

13

2.50 3.00 3.50 4.00 4.50

18 22 24 26 22

46 30 22 23 12

47 32 23 24 13

48 33 24 25 14

49 34 25 26 15

50 36 26 27 16

51 37 27 28 17

52 38 28 29 19

53 39 30 30 20

54 40 31 31 21

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