Assigment 2.docx

SKL 3013: CHEMISTRY LABORATORY MANAGEMENT TECHNIQUES

EXPERIMENT 2: APPARATUS AND MEASUREMENT IN THE LABORATORY

NAME

NO MATRIC

FATINI ZAKIRAH BINTI ZAHARIN

D20161073878

NOOR NADHIRAH BINTI HUSAINI

D20161073906

GROUP

:A

SEMESTER

: 2 2017/2018

DATE EXPERIMENT : 2 MARCH 2018 LECTURER

: DR. LEE TIEN TIEN

2.1 OBJECTIVES Upon completion of this activity, students should be able to: 1. Know the correct apparatus to be used for transferring samples e.g.: solids and liquid, 2. Apply the concept of accuracy and precision in measurement, 3. Operate the electronic balance and record data with the correct figures, 4. Apply the technique of using volumetric apparatus such as pipette and graduated cylinder, 5. Apply the derivative of measurement for example to determine the density of the solid objects.

2.2 PROCEDURES ACTIVITY 1: MASS

ACTIVITY 2: VOLUME

2.3 RESULTS ACTIVITY 1: MASS Top-Loading Balance Reading I 31.11g 22.01g 31.11 + 22.01 = 53.12g 53.15g 53.15 - 53.12 = 0.03g

(1) Mass of crucible (2) Mass of crucible lid (3) Sum of (1) and (2) (4) Mass of crucible and lid (5) Difference between (3) and (4) (6) Average value of (4)

II 31.20g 21.91g 31.20 + 21.91 = 53.11g 53.17g 53.17 - 53.11 = 0.06g

53.15 + 53.17 = 53.16𝑔 2 (7) Relative deviation of (4) 𝐷𝑎𝑡𝑎 (4)−𝐷𝑎𝑡𝑎 (6) 𝐷𝑎𝑡𝑎 (6)

𝑥 100

(8) Average of relative deviation

53.15 − 53.16 | | 𝑥 100 53.16

53.17 − 53.16 | | 𝑥 100 53.16

= 0.0188% = 0.0188% 0.0188 + 0.0188 = 0.0188% 2

Analytical Balance Reading (1) Mass of crucible (2) Mass of crucible lid (3) Sum of (1) and (2) (4) Mass of crucible and lid (5) Difference between (3) and (4) (6) Average value of (4)

(7) Relative deviation of (4) 𝐷𝑎𝑡𝑎 (4)−𝐷𝑎𝑡𝑎 (6) 𝐷𝑎𝑡𝑎 (6)

𝑥 100

(8) Average of relative deviation

I 31.1791g 21.9285g 31.1791 + 21.9285 = 53.1076g 53.1622g

II 31.1781g 21.9843g 31.1781 + 21.9843 = 53.1624g 53.1616g

53.1622 - 53.1076 = 53.1624 - 53.1616 = 0.0546g 0.0008g 53.1622 + 53.1616 = 53.1619𝑔 2 53.1622 − 53.1619 53.1624 − 53.1619 | | 𝑥 100 | | 𝑥 100 53.1619 53.1619 = 5.6431X10−4 % =5.6431X10−4 % 5.6431X10−4 + 5.6431X10−4 = 5.6431X10−4 % 2

ACTIVITY 2: VOLUME Graduated Cylinder Reading (1) Mass of beaker (2) Mass of beaker and water (3) Mass of water (2) – (1) (4) Average value of (3)

I 42.3036g 52.0991g

II 30.0247g 39.8851g

52.0991 - 42.3036 = 39.8851 – 30.0247 = 9.7955g 9.8604g 9.7955 − 9.8604 = 9.8280𝑔 2 (5) Calculated mass of m = 𝜌𝑣 water = (0.9970)(10) = 9.9700𝑔 9.8604 − 9.9700 9.7955 − 9.9700 (6) Relative error of (3) | 𝑥 100 | | 𝑥 100 | 9.9700 9.9700 𝐷𝑎𝑡𝑎 (3)−𝐷𝑎𝑡𝑎 (5) = 1.0993% 𝑥 100 = 1.7503 % 𝐷𝑎𝑡𝑎 (5) (7) Average of relative error (8) Relative deviation of (3) 𝐷𝑎𝑡𝑎 (3)−𝐷𝑎𝑡𝑎 (4) 𝐷𝑎𝑡𝑎 (4)

1.7503 + 1.0993 = 1.4248 % 2 9.8604 − 9.8280 9.7955 − 9.8280 𝑥 100 𝑥 100 9.8280 9.8280 = 0.3302% = 0.3302%

𝑥 100

(9) Average of relative deviation

0.3302 + 0.3302 = 0.3302% 2

Temperature of water = 25℃ From the table 2.1, density of water = 0.9970 g/mL

Pipette Reading (1) Mass of beaker (2) Mass of beaker and water (3) Mass of water (2) – (1) (4) Average value of (3) (5) Calculated mass of water (6) Relative error of (3) 𝐷𝑎𝑡𝑎 (3)−𝐷𝑎𝑡𝑎 (5) 𝐷𝑎𝑡𝑎 (5)

𝑥 100

(7) Average of relative error (8) Relative deviation of (3) 𝐷𝑎𝑡𝑎 (3)−𝐷𝑎𝑡𝑎 (4) 𝐷𝑎𝑡𝑎 (4)

𝑥 100

(9) Average of relative deviation

I 35.0493g 44.7523g

II 29.3146g 38.9758g

44.7523 – 35.0493 = 38.9758 – 29.3146 = 9.7030 g 9.6612g 9.7030 + 9.6612 = 9.6821𝑔 2 m = 𝜌𝑣 = (0.9970)(10) = 9.9700𝑔 9.7030 − 9.9700 9.6612 − 9.9700 | | 𝑥 100 | | 𝑥 100 9.9700 9.9700 = 2.6780 % = 3.0970 % 2.6780 + 3.0970 = 0.02888 % 2 9.7030 − 9.6821 9.6612 − 9.6821 𝑥 100 𝑥 100 9.6821 9.6821 = 0.2169% = 0.2169% 0.2159 + 0.2159 = 0.2169% 2

Temperature of water = 25℃ From table 2.1, density of water = 0.9970 g/mL

2.4 DISCUSSION: ACTIVITY 1: For the activity 1, we had to compare the value of average relative between top-loading balance and analytical balance in order to determine the most precision apparatus to weighing the crucible. From the experiment, the average relative deviation for toploading balance are 0.0188%. For analytical balance, the average relative deviation is 5.6431X10−4 %. So, we can conclude that the most precision apparatus to weighing crucible is by using analytical balance because it has lower percent than top-loading balance. Based on the theory, analytical balance is precise than top-loading balance. The experiment is success because the result is followed the theory.

ACTIVITY 2: For the activity 2, we had to compare the value of average relative error and average relative deviation between graduated cylinder and pipette in order to determine the most accuracy and precision apparatus to measure the volume of water. From the experiment, the average relative error and the average relative deviation for graduated cylinder are 1.4248% and 0.3302% respectively. For pipette, the average relative error is 0.02888% and the average relative deviation is 0.2169%. So, we can conclude that the most accuracy and precision apparatus to measure the volume of water by using pipette because it has lower percent relative error and relative deviation than graduated cylinder. We also repeated two times of reading to make sure the precision is obtained. This is important because if we only do for one trial, it will affect the result and the actual reading of this experiment cannot be obtained. So, we need to repeat and read it carefully to get a better result. Based on the theory, pipette is more accurate and precise than graduated cylinder. The experiment is success because the result is followed the theory.

2.5 CONCLUSIONS: In conclusion, the theory said that the most precise apparatus to weighing are toploading balance and the apparatus to measure at the most precise and accurate was pipette. From this experiment, we had obtained the same result as the theory which got top-loading balance as the most precise apparatus to weighing and pipette as the most accurate and precise apparatus on measure the volume. So, our experiment was success.

2.6 REFERENCES:

GCC CHM151LL: Accuracy and percision of laboratory glassware: Determining the density of water. (2009). Retrieved from web.gccaz.edu: http://web.gccaz.edu/~rob2108739/Density%20of%20Water/A%20and%20P%2 0Lab%20Glassware.pdf Christian, D. G. Analytical Chemistry, 6thEdition, John Wiley & Sons Inc

2.7 APPENDIX: