FACULTY OF RESOURCE SCIENCE AND TECHNOLOGY
DEPARTMENT OF CHEMISTRY
STK 1201- Practical Physical Chemistry 1
TITLE OF EXPERIMENT:
DATE OF EXPERIMENT:2066925698418288006984
GROUP MEMBERS & MATRIC
LAB FACILITATOR :
EXPERIMENT 1: GLASSWARE CALLIBRATION
Usually, everyone makes mistakes when we are doing experiment especially quantitative experiment which is involved the calculation and the reading of volume correctly. Basically, all volumetric glassware is calibrated with markings used to determine a speci?c volume of liquid to varying degrees of accuracy (Walker, 2011). Calibration is the common procedure by which an expressed measure, for example, the volume of a container is checked for precision and accuracy.
For the glassware calibration experiment, we divided into three part which is pipette calibration, burette calibration and volumetric flask calibration.
Part A: Pipette calibration
Volumetric pipette is calibrated to deliver an exact volume of liquid or solution. Volumetric pipette has only one calibration mark. First of all, we put a small empty beaker on the analytical balance and tare the balance to obtain the mass of empty beaker which is 47.057 g for the first trial. Next, we filled the pipette to the calibration mark with distilled water and we ensured that the tip of the pipette does not touch the bottom of the beaker as the tip is very fragile. Then, we drained the water into the beaker. However, we make sure that a small amount of solution remained at the tip of pipette by carefully touch the tip to the side of beaker. As the pipette is specifically calibrated, so that this should not affect the amount of water that we transferred. After that, the mass of water transferred is recorded.
Then, water temperature is recorded by using the thermometer which is 22°C. The 22°C of water temperature indicated the density of water which is 0.997770 g/mL. To minimize the error during calibration, we tare the balance again and repeat this procedure twice.
Part B: Burette Calibration
Burette allows you to deliver volumes of liquid accurately that cannot be measured by volumetric pipette or micropipettors. The proper use of burette is essential to accurate titration analyses. Firstly, we filled the burette with distilled water. To obtain a good result, we got rid the air bubbles by letting the solution drain until the air bubbles are removed. Next, we weighed a clean and dry Erlenmeyer flask and the mass is recorded to the nearest 0.0001 g which is 51.412g.
After that, 5 mL of distilled water is drained nominally into the weighed Erlenmeyer flask. Drain water slowly until the meniscus is at the 0.00 mL mark. Touch the tip of the burette to the side of a beaker to remove the drop hanging from the tip. To avoid the errors during the reading of initial and final reading scale of burette, we used a piece of white people ti see the scale of burette clearly and the crucial part is we took the reading at the particular part of meniscus and always measure this part. Then, we weighed the flask again to determine the mass of water delivered.
Basically, we repeated the process for trial 2, and trial 3 while we redo all the procedure by changing to 10 mL, 15mL, 20mL and 25mL. with the information of density, we managed to determine the true volume of water delivered.
Part C: Volumetric flask calibration
Volumetric flasks are calibrated to contain an exact volume of solution when the solution level is exactly at the mark on the neck of the flask which the bottom of the meniscus should lie exactly at this mark. We weighed the dry volumetric flask with stopper and the mass is recorded. Next, we filled the volumetric flask to the mark with distilled water and the mass of volumetric flask after filled with water is recorded. The same goes to part C which we repeated all the procedure twice and calculated the actual volume of distilled water contained.
Generally for our result we did not managed to obtain an accurate result due to certain error that could be parallax error or random error. However, we managed to obtain a very precise result overall.
Therefore, the mass of the liquid contained or dispensed by the glassware will be measured and the corresponding volume calculated using the density of the liquid. However, a relatively small change in temperature causes a change in the liquid’s volume and thus its density.
GENERAL CHEMISTRY 2 LABS using argument-driven inquiry (first edition, volumetric glassware)
Copyright © 2012 Advanced Instructional Systems, Inc. and and Joi Phelps Walker. Portions © 2011 North Carolina State University
https://studymoose.com/lab-report-calibration-of-volumetric-flask-essayLab report calibration of volumetric flask. (2016, Apr 28). Retrieved from https://studymoose.com/lab-report-calibration-of-volumetric-flask-essay