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Unformatted text preview: Experimental Data General Chemistry I and II Lab Manual up to the line and read the corresponding boiling point. This turns out to be about 55 o C.
This is actually a terrible result, but it is what we found. Always be true to your data. If
a result is far from correct, write a little paragraph on what you think may be the reason
behind the poor result.
Always include a title with your graph, as well as your name and the date. The
title is always something along the lines of “Graph of y versus x:. When we use
“versus”, by convention, it is always y versus x. You may include a sub-title if you like,
which is often helpful for similar plots from different sets of data.
REMEMBER: (1) ALWAYS use the ENTIRE piece of graph paper.
(2) ALWAYS label your axes including units and division sizes.
(3) ALWAYS draw the line through as many experimental points as possible.
(4) ALWAYS include a title, na me and date.
These few rules will help to ensure that you make the best possible graphs. Dakota State University page 217 of 232 Plotting Experimental Data General Chemistry I and II Lab Manual Appendix: Example of graphing; boiling points versus molecular weight.
Molecular Formula/Name Molecular Weight in g/mol
Boiling Point in o C 1 C6 H14 / Hexane 86.18 123 C7 H16 / Heptane 100.21 104 C8 H18 / Octane 114.23 124 C9 H20 / Nonane 128.26 145 C10 H22 / Decane 142.29 198 1 In order to simulate expermimental data, this column was obtained by taking the
published boiling points for these liquids and randomly adding +- 15% error.
x axis range (molecular weight): 10 - 150 g/mol (this will be the width of the
y axis range (boiling point): 50 - 200 oC (this will be the length of the graph
Graph Paper Divisions:
x (width): 39 before axis; 35 after axis; (150-10)/35 = 4 g/mol per division
y (length): 52 before axis; 50 after axis; (200-50)/50 = 3 o C per division
Boiling point of methane (16 g/mol) from the line: approx. 55 o C. Dakota State University page 218 of 232 Factor Label Method General Chemistry I and II Lab Manual Factor Label Method What is it? The factor label method is an algebra intensive method of problem solving
Where would I use it? The factor label method is generally applicable to most problem
What is the benefit? The factor label method has two main benefits making it a
powerful technique well worth the time and effort to learn it. First, utilizing the factor
label method can often predict when an answer is wrong. Second, utilization of the factor
label method often removes the necessity of memorization of many formulas and
What are the drawbacks? Being a problem solving system, it is not for everybody. It
seems cumbersome at first, difficult to get a handle on, and other problem solving
techniques exist that work well also. However, many students have never been taught
any problem solving techniques, and would find this beneficial. However, it will take
some work before the student is comfortable with the method.
The Factor Label Method Foundation:
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