Lab Data and Calculaons: In the shaded area below, enter the data you collected in lab. Once you
Submit and Confirm your lab data, the program will allow ... [Show More] you to enter answers to the various lab
calculaons. If you Submit / Confirm incorrect data, you can correct your data with the links at the top
of the page.
Note: If you change your data the program remembers any points you lost using the incorrect data
and deducts those points from your total grade.
Throughout the use of Chem21 Online Lab Submission you will enter answers to calculaons. Your
Instructor has established tolerances which the Chem21 program uses to grade your answer. If you are
expected to round your answer to the correct number of Significant Figures, you will be nofied on
the webpage; otherwise, you need only enter a number that falls between the correct number minus
the tolerance and the correct number plus the tolerance. The tolerance for any Chem21 calculaon is
found in the right side panel once you open a calculaon. If the Tolerance says ± 2 in 3 SF, it means
that if your answer falls between the correct answer minus 2 in the 3 Significant Figure AND the
correct answer plus 2 in the 3 Significant Figure, Chem21 will count it as correct.
You should always look at the stated Tolerance in the side panel so you know the MINIMUM number
of Significant Figures you must use to report your answer.
To use scienfic notaon you will use the E notaon. For example, 4.5 x 10 would be entered as
Note: All essay answers throughout the semester must be composed in the
html text editor below.
The objective of investigating the reversibility of a chemical reaction was achieved by adding NaOH (base)
dropwise to the solution until the color change occured and then adding HNO (acid) dropwise until the color
changed back. The colors switched back and forth between orange and yellow which demonstrated the
reversibility of a chemical reaction. The second objective of evaluating the relative changes in equilibrium
position of a series of metal aquo complex ions upon addition of chloride ion was achieved by adding 12M
HCL dropwise into test tubes of each until a definite color change occurred. The objective of using Le
Chatelier's principle to rationalize the perturbation of an equilibrium system in a variety of ways was
achieved by seeing how different things affected the color: adding water, KNCS, AgNO , and temperature
changes. The concepts that relate to lecture are concentration, equilibrium, acids and bases, and Le
Chatelier's principle. The lab techniques used were using an analytical balance, using a disposable pipet and
measuring drops, and using a hot plate to make a warm bath and ice to make an ice bath. [Show Less]