In ismayc/chemistr: Facilitates use of R functions and R Markdown files for Chemistry lab reports

library(chemistr)

Link to the Project for this file, along with the file name

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Results

# Here is where you input your raw data from your experiment.

Concentration<- c() #include the final concentration in your dilutions in units of Molarity.  

Transmittance <- c() #Percent transmittance.  Make sure only data that is within the quantifiable range (1-80%) is included

data <- data.frame(Concentration, Transmittance) #This creates a table of data.  For more info on data frames see: https://www.tutorialspoint.com/r/r_data_frames.htm

Intensity-Independent Model

#The first mathematical model you will test is the intensity independent model which predicts a linear relationship between %T and concentration.  In this case you can directly fit concentration versus transmittance to a straight line fit.

#To create the scatter plot, go to your linear regression lab report or the Chem_ScatterPlot template and copy and paste the code that will 1) create a scatter plot, using chem_scatter function 2) extract the fit data using the lm function and 3) provide a summary of the fit data using summary.

#Change the code to represent the variables names in your data frame.

#Once you have run this chunk, write a caption after fig.cap = "Insert Caption" in the R chunk heading above.  In your caption (sentence format) include the wavelength being tested, size of the cuvette, mathematical model you are testing and the details of the fit (slope +/- error and Y-intercept +/- error and R^2)

Intensity-Dependent Model

#In this chunk you will test the intensity dependent model which predicts a exponential relationship between %T and concentration.  To fit with the straight line lm() function, we need to rewrite the relationship as a semi-log plot in which the log10(Y) is graphed on the Y axis instead of just Y.

#Just as in the previous chunk you will need to create a graph, extract the fit information and display a summary of it.

#Also, your caption should include the same type of information as the previous chunk (in a complete sentence).

Discussion

Question 1: State the conclusion (claim) you can make about the mathematical model that best describes light and concentration. Make sure you report the predicted model and use your graph results above as evidence to support your conclusion.

Example wording (should be deleted): A linear relationship was observed between apples and time because it fit the data better than the semi-log model. This is measured by the higher R^2 value in the linear plot (Figure 1) versus the semi-log plot (Figure 2). A linear prediction indicates that apples were eaten consistently over the course of a day.

Question 2:The relationship between light transmittance and concentration is a well studied relationship that has been given the name: the Beer-Lambert Law. Look up this equation and report it (include a citation with your source, how to cite is found on Lab Moodle: https://moodle.reed.edu/mod/page/view.php?id=178279). How does it compare to your results? (Note: Absorbance is not the same as Transmittance, so you may need to look up how they are related)

Delete this and write your answer.

Qustion 3: Explain why you blanked the cuvette with DI water instead of just using an empty cuvette. (It may be helpful to consider that the stock solution of FD&C blue dye is made by adding dry powder that contains the dye to DI water to make the solution).

Delete this and write your answer.

ismayc/chemistr documentation built on Feb. 4, 2023, 12:44 p.m.