CHEM 2120 Experiment 1
Lab Skills: Report Sheet
Kuganesh Ketheesh & Student #: 100598968
* Please re-save this document with your name in place of ketheesh_kuganesh
Instructions
Using the pictures and videos in the CHEM 2120 Exp1 Lab Skills W21 document, fill in the information
below. You can type you answers directly into this document or write it by hand; however, all
submissions are done digitally through turnitin.com.
Weighing Out a Sample: Describe the errors seen in the picture and explain the problems that could
arise.
The problem with this is that the person is directly measuring out their solid on the analytical balance, this is an
error because it is a delicate equipment that may cause errors just simply by vibrations. A good weighing technique
is very important to success in all aspects of chemistry and the measurement of mass. For the greatest efficiency
the proper balance must be chosen, and the procedure must be done correct. The proper use of an analytical
balance is to tare it to zero every time and to keep all the door closed and to allow the mass to be analyzed within
+- 0.0001g. By not closing the doors of the balance, air currents can affect the measured mass if the person is
leaning on the table that could also lead to many issues that would adversely affect the measurement. Essentially,
the person measuring out the solid should know that if they needed to still finish measuring out the sample, they
should do that beforehand. A great solution for this is if the person in the photo had performed weight by
difference. First, all they would have to do is weigh out the sample on an open pan balance, preferably using a
small beaker or weighing vial. The beaker should then be measured on the analytical mass with all door closed, so
that vibrations from adding mass directly on analytical balance and air current from keeping the doors open can be
exempt. Furthermore, they would have to pour the contents of the small beaker into a receiving vessel and simply
re-weigh the now close to empty small beaker. Finally, they would have to perform calculations in order to
determine the amount of mass transferred by doing (mass of solid +beaker) subtract (close to emptied beaker).
-Chemical spillage on an analytical balance can lead to different values for measurements at different times (it can
lead to fluctuation; this can go on to mess up any further calculations using the those mass values recorded. By
using an open pan balance and collecting the sample in a small vial or beaker before using the analytical balance
you can ensure correct mass measurements, especially ones that don’t change while you do continuous
measurements.
In general, all step and procedures required in the lab to transfer and correctly measure a solid should be followed
in as avoiding using a analytical balance just in case to prevent any miscalculation due to errors such as chemical
spillage as well.
Preparing a TLC Plate: Describe the errors seen in the two pictures and explain what would happen
if the experiment was allowed to run as shown.
The errors seen in the two pictures is that the spotted sample to be analyzed are not at the bottom but
at the top.
1 | CHEM2120W21
Lab Skills: Report Sheet
Kuganesh Ketheesh & Student #: 100598968
* Please re-save this document with your name in place of ketheesh_kuganesh
Instructions
Using the pictures and videos in the CHEM 2120 Exp1 Lab Skills W21 document, fill in the information
below. You can type you answers directly into this document or write it by hand; however, all
submissions are done digitally through turnitin.com.
Weighing Out a Sample: Describe the errors seen in the picture and explain the problems that could
arise.
The problem with this is that the person is directly measuring out their solid on the analytical balance, this is an
error because it is a delicate equipment that may cause errors just simply by vibrations. A good weighing technique
is very important to success in all aspects of chemistry and the measurement of mass. For the greatest efficiency
the proper balance must be chosen, and the procedure must be done correct. The proper use of an analytical
balance is to tare it to zero every time and to keep all the door closed and to allow the mass to be analyzed within
+- 0.0001g. By not closing the doors of the balance, air currents can affect the measured mass if the person is
leaning on the table that could also lead to many issues that would adversely affect the measurement. Essentially,
the person measuring out the solid should know that if they needed to still finish measuring out the sample, they
should do that beforehand. A great solution for this is if the person in the photo had performed weight by
difference. First, all they would have to do is weigh out the sample on an open pan balance, preferably using a
small beaker or weighing vial. The beaker should then be measured on the analytical mass with all door closed, so
that vibrations from adding mass directly on analytical balance and air current from keeping the doors open can be
exempt. Furthermore, they would have to pour the contents of the small beaker into a receiving vessel and simply
re-weigh the now close to empty small beaker. Finally, they would have to perform calculations in order to
determine the amount of mass transferred by doing (mass of solid +beaker) subtract (close to emptied beaker).
-Chemical spillage on an analytical balance can lead to different values for measurements at different times (it can
lead to fluctuation; this can go on to mess up any further calculations using the those mass values recorded. By
using an open pan balance and collecting the sample in a small vial or beaker before using the analytical balance
you can ensure correct mass measurements, especially ones that don’t change while you do continuous
measurements.
In general, all step and procedures required in the lab to transfer and correctly measure a solid should be followed
in as avoiding using a analytical balance just in case to prevent any miscalculation due to errors such as chemical
spillage as well.
Preparing a TLC Plate: Describe the errors seen in the two pictures and explain what would happen
if the experiment was allowed to run as shown.
The errors seen in the two pictures is that the spotted sample to be analyzed are not at the bottom but
at the top.
1 | CHEM2120W21
