Common Assignment Chem 1 Review and Excel Graphing

Homework answers / question annal / CH110 Consignment:  To Excel in Chemistry Consignment Instructions:  Hand in the fill-in-the-blanks sheets along with any supporting evidence such as required plots and tabular array of values

CH110 Assignment:  To Excel in Chemistry Consignment Instructions:  Paw in the fill-in-the-blanks sheets along with any supporting evidence such as required plots and tabular array of values

Chemical science

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CH110 ASSIGNMENT:  To Excel in Chemistry

Consignment Instructions:  Manus in the fill-in-the-blanks sheets along with any supporting evidence such as required plots and table of values.  All work must be completed in pen (not pencil) or typed (preferred) directly in this document.  No other lab study component is required for this consignment.  Note that fifteen marks out of 100 are assigned for including units and the correct number of pregnant digits and then double check your piece of work before handing in.

DUE DATE: Tuesday Nov 10 ^th , eleven:59PM to the online MyLS CH110 lab dropbox as ONE DOCUMENT/submission.

Google Sheets CANNOT exist used to consummate this assignment. Exist sure to download the gratuitous version of Microsoft Office available to all WLU students.

OBJECTIVE

To manipulate chemical information in a graphing program and to perform linear regression and data assay.   To larn techniques to write proper computer generated scientific lab reports.

Form Learning Outcome

? Demonstrate competency in linear graphical information analysis

In chemistry, is information technology frequently useful to decide the mathematical relationship between two physical parameters.  Graphs are useful tools that can help observe and elucidate such relationships. Showtime, plotting a graph provides a visual image of data and any trends therein.  Second, analysis of the graph tin can provide a mathematical expression that describes the human relationship betwixt the two physical parameters.  Third, graphs tin can be used to estimate the values of the physical parameters that are beyond the range of the data set up and that are between observed information points; the one-time process is called extrapolation while the latter is called interpolation.

One common relationship betwixt physical parameters is a linear relationship.  A linear human relationship occurs when 2 or more quantities are proportional to ane some other.  When a linear relationship exists betwixt physical parameters and those parameters are graphed, a distinct pattern is observed—the plotted points resemble points on a straight line.  A straight line can be fitted to the plotted points. Historically, plumbing fixtures a line to plotted points was done past hand and with a straight edge but today modern software is used for this purpose.  Software uses a statistical technique known as linear regression to create a directly line that is the best fit between all the data points on a plot. In addition, software oft provides a mathematical expression of the line, commonly in the familiar slope-intercept grade: y = mx + b.  This equation expresses the mathematical relationship betwixt the 2 variables plotted, and allows extrapolation and interpolation.  Figure one shows the full general form for a straight line graph.

Gradient-intercept form of best-fit line:

y = mx + b

Δy

y -intercept: b

Δ10 Gradient: m = Δy/Δx = y ₂ − y ₁ /ten ₂ − ten _ane

10 - axis

Effigy ane :  The general course of a graph displaying graph components.

Computer spreadsheets are powerful tools for manipulating and graphing quantitative data.  In this do, the spreadsheet program Microsoft Excel ^? will be used for this purpose.  In item, students volition acquire to use Excel in order to explore a number of linear graphical relationships.

Apple Computer Users:  These instructions were written to use to Microsoft Excel PC.  There may exist some difficulty in applying these instructions if an Apple computer arrangement is used. However, the procedures for Excel for Mac should be similar to those provided here.  In that location are two options: Complete the assignment using your Apple computer or utilise a schoolhouse computer that has Microsoft Excel installed.

Part one: Simple Linear Plot

Scenario:  A gas laws experiment is designed to measure the book of one mole of helium gas at a variety of different temperatures, while keeping the gas pressure level constant at 758 Torr.  The data that was collected is given below in table ane.

Table i : Temperature and Book of Helium information collected in a gas laws experiment.

Temperature (K)	Volume of Helium (L)
203	fourteen.3
243	17.2
283	23.1
323	25.nine
363	31.5

1. Launch the Excel program.  Go to the Outset button, located at the bottom left on the screen, and then click Programs, followed past Microsoft Excel or click on your Excel icon on the desktop screen.  If a new workbook does not open up automatically, click "File", and then "New" and and so "Bare Workbook".
2. Enter the above data into the start two columns (A and B) in the spreadsheet.
   • Ensure the first row contains the cavalcade labels.
   • One way to plot an xy graph is begun past placing the data in columns so that the columns are in a specified order.  The x values must be entered to the left of the y values in the spreadsheet.  Remember that the independent variable, the one that you, equally the experimenter, have control of, is plotted along the x- axis while the dependent variable, the measured data, is plotted forth the y-axis.
   • Highlight cavalcade A past clicking on the column letter of the alphabet heading.  Select cavalcade A and B past holding downwardly the left mouse button and dragging to cavalcade B.  With both columns selected, move the cursor to the border that lies between column A and B until the cursor becomes a vertical line with arrows on either side.   Double clicking will auto-fit the contents of both columns and so that the headings are clearly visible. Clicking on any cell will deselect the columns.  Alternatively, the "Format" button on the "Home" tab tin can be used to set column widths.
3. Highlight the prepare of information only not the column labels that y'all wish to plot (Figure 2).

Figure 2 :  Highlighted data set up of Temperature and Volume of Helium

Click on the "Insert" tab at the top left, followed past "Besprinkle" button (Figure 3).

 Highlighting the Insert Tab which displays the Scatter button

Choose the scatter graph that shows data points just.  This is the option labeled "Scatter with Only Markers" (Effigy four).

Figure 4 :  Scatter with Merely Marks button

Yous should now see a besprinkle plot on your Excel screen, which provides a preview of your graph (Effigy v).

Figure 5 : Preview of Excel graph with information from tabular array 1.

If all looks well, it is fourth dimension to add titles and label the axes of your graph.

• Click inside the nautical chart. "Chart Tools", which is a grouping of iii tabs (Pattern, Layout, Format), will announced.
• Click on the "Layout" tab, located under "Chart Tools".
• Click on "Chart Title" and so "Above Chart" to add a title.  The default title, which is automatically added by Excel, is "Chart Title".  This is never an advisable championship for a scientific graph.  The championship of a graph should be given a meaningful, explanatory title and then that when presented with your graph the reader should be able to determine what is plotted quickly and easily.   The championship should start with "y versus 10", where y is the dependent variable and x is the independent variable and followed by a description of your system. For example, the title "Volume versus Force per unit area for One Mole of Air at 298 Kelvin" describes a plot of volume, on the y-axis, and force per unit area, on the x- axis, for ane mole of air at a constant temperature of 298 Kelvin.

To change the default title to the title yous have called, click inside the text box to identify the cursor in the box and so delete the default championship and add together your title.

• Click on "Axis Titles", which is located to the right of the "Chart Title" button.  Select "Primary Horizontal Axis Title" and so select "Championship Below Centrality" to enter the horizontal axis label.  Click on "Chief Vertical Axis Title" and and then "Rotated Championship" to add the vertical axis label.  The centrality labels must include the physical measurement (volume, temperature, time, etc.) and the units of measurement.  Figure vi shows the

location of the Nautical chart Title and Axis Title buttons on the Layout tab.

 Nautical chart Title and Axis Title buttons needed to create chart and axis titles.

4. The next step is to fit a straight line to these plotted data points.  In Excel a line that is fit to information is called a "trendline".  A trendline represents the best possible fit of a straight line to your information.  To exercise this you offset need to "activate" the data points.  Do this by clicking on any 1 of the data points.  When you lot do this, all the information points will announced highlighted.

Now click on the "Trendline" button which is located in the "Layout" tab under "Chart Tools".  Choose "More Trendline Options".  The "Format Trendline" window should now appear (Figure seven).

The radio button for the "Linear" trendline, nether "Tendency/Regression Type" should be selected, it is usually the default trendline selection, but if it is not, select it.

Now select the "Brandish Equation on Chart" box and the "Display R-squared value on

Chart" box by clicking in the check-box to the left of these options.  So click the

 Format trendline window displayed in Excel spreadsheet.

5. The equation that now appears on your graph is the equation of the fitted trendline and appears in the gradient-intercept form of a straight line.  The R ² value, known equally the coefficient of determination or goodness of fit parameter, provides a measure of how well the equation fits the data.  The closer the R ^two value is to ane, the improve the fit.  By and large, R ² values of 0.95 or college are considered good fits.   The program will always fit a trendline to the data no matter how well or how poor the direct line fits the data.  Y'all must guess the quality of the fit and the suitability of this blazon of fit to your data set.  Ane style of doing this is to use the R ² value.
6. In our plot there are no information points in the region of 0 – 150 on the x- axis, see Effigy 6.  To better present the plot, we need to remove this unnecessary surface area from the plot.  We practice this past adjusting the 10-centrality scale.  Click on whatsoever 1 of the numbers on the x- axis.  And then, click "Axes" nether the Chart Tools Layout tab.  Select "Master Horizontal Axis" and then "More Primary Horizontal Centrality Options" from the dropdown carte.  This will open the "Format Centrality" window.  Ensure "Axis Options" is selected (Figure 8).  Select the "Stock-still" radio button which is located to the right of the "Minimum" option.  This will actuate the box located to the right of the radio button. Type 150.0 in the box.  This sets the minimum x- axis value to 150.  Press Enter.  The Format Axis window will shut and the x- axis of your plot should now testify a range of 150 to  400.

 Axis options window open to change minimum x-axis value.

7. To remove the legend from the right paw side of the graph, click on the legend box and printing "delete" on the keyboard.   Alternatively, select the "Layout" tab and click on "Legend". Select "None".
8. Impress out a full size copy of this prepared graph and staple it to your report.  Ensure your graph is already selected, and so y'all should but have to cull "Impress" to obtain a full-size printout.  Then record the post-obit information on your study:
   • the equation of the best-fit trendline to your data
   • the gradient of the trendline
   • the y- intercept of the trendline
   • whether the fit of the line to the data is good or poor, and why.
1. Graphing the five data points of the gas constabulary experiment allows united states to recognize a relationship betwixt gas book and temperature.  The graph contains a visual and mathematical representation of that relationship.  The graph can now be used to make predictions of gas book and temperature.  For example, suppose the 1 mole sample of helium gas is cooled until its volume is measured to be 10.5 L and you are asked to make up one's mind the gas temperature.  The volume 10.5 L falls outside the range of the plotted data.  How tin can you find the temperature if it doesn't autumn betwixt known points?  There are ii means to do this.

Method (1): Graphical Extrapolation.

Graphical extrapolation uses the graph and the best-fit-line to estimate the coordinates of a point that is beyond the range of the data ready. This is accomplished by extending the best-fit-line and measuring on the graph the coordinates of the desired point.

• Click on the "Layout" tab along the superlative menu, then on "Trendline" and then "More Trendline Options".  The "Format Trendline" window will open (Figure 9).
• In the section labeled "Forecast" you lot want to enter a number in the box labeled "Backward". In Excel, the backward direction is to the left of the trendline.  To decide what number to enter, look at your graph to see how far back along the 10- axis you lot need to become in order to cover the area where the volume is x.5 50.  In the Forecast box you will see the word "periods" to the right of the forrard and astern boxes.  The "periods" term refers to "units of", then in this case, one menstruum equals one caste Kelvin.   Enter the correct number of Kelvins required to go dorsum past x.v L. Click "Close" and the line on your graph should now exist extended in the backward management.

Displays the backward forecast box in the format trendline window.

• Now apply your graph to gauge the ten value by hand-drawing a straight line downwardly from y = 10.5 L to the ten-axis using a ruler and pen.  Record this value on your written report.

Method (2): Extrapolation via Equation of the line.

This method is largely a mathematical method, simply the equation of the best-fit line is needed.

• Enter the value for book into the equation of the trendline and solve for the unknown temperature.
• Testify how yous solved for temperature and record your answer on your report.
• In general, using the equation to extrapolate is more precise than graphical extrapolation.

Scenario:  A 2d gas laws experiment is designed to measure how quickly helium gas diffuses from a source to a detector ten meters away.  The temperature of the sourced is varied and the time of diffusion is measured.  The data collected from the experiment are given in Table ii.

Table ii:  Temperature and Fourth dimension of Diffusion Data for Helium Gas.

Temperature (Yard)	Time of Diffusion (ms)
ii.00 × ten two	nine.72
3.00 × 10 2	7.93
iv.00 × ten ii	half dozen.87
5.00 × 10 two	half-dozen.15
half-dozen.00 × x ii	5.61
7.00 × ten 2	5.19
8.00 × ten ii	4.86

1. Obtain a new worksheet in Excel past clicking on the Sheet 2 tab at the lesser left of the window.  Enter the data from Table 2 into columns A and B.  To enter the temperature values in scientific notation, you must showtime format the cells in which the values are to be entered.
   • Select the cells you want to format.
   • On the "Home" tab select "Number" to open the "Format Cells" window.
   • Click on the "Number" tab
   • On the "Number" tab, click Scientific in the Category list.
   • In the "Decimal places" box, enter the number of decimal places that you want to display. Nosotros desire 2 decimal places in this example.  We apply scientific notation for the temperature values so nosotros can retain three pregnant digits.
   • Click "OK"
   • Enter the temperature values in the cells without scientific notation, for example ii.00×10 ² is entered every bit 200.

Create a plot of time versus temperature. Follow the process as outlined in Office i. Include the R ² value.  Answer these questions in your lab report: Why is time plotted on the y-centrality?  Which set of information is placed on the left in the Excel worksheet?

2. You volition brand iii additional graphs involving this information. For each plot yous will convert the temperature values into temperature related values and then plot these against fourth dimension of

improvidence.  You will catechumen each temperature value in Table 2 into

1. 1. the natural logarithm of the temperature value,
   2. the square root of the temperature value and
   3. the changed of the foursquare root of the temperature value.

You will instruct Excel to fit a trendline and summate the R ² value for each of our plots.  You will compare all iv graphs and utilise the R ² values to make up one's mind which plot gives the virtually linear relationship betwixt the two variables.

3. Using functions to dispense data values in Excel is quite straightforward.  As an case, follow the process beneath to obtain a column of  the natural logarithm of the temperature values:
   • To enter the natural logarithm of the beginning temperature value, follow these instructions: Select cell C2.  Type "=LN(A2)", without quotes.  Press enter.  Alternatively, you lot can type "=LN()" and so put the cursor betwixt the parentheses and click on prison cell A2 and printing enter.  The equals symbol "=" indicates to Excel that you are entering a function. The "LN(A2)" function instructs Excel to calculate the natural logarithm of the value in cell A2, the first temperature value.  The natural logarithm of the value in cell A2 should now appear in cell C2.    Information technology is always a good idea to check that Excel is making the correct calculation.  Utilize your estimator to calculate the natural logarithm of the value in cell A2 and compare it to the value in cell C2.
   • To quickly create the formulas for the residue of the cells in cavalcade C, you will use the make full handle selection.  Click on cell C2, the cell that contains the natural logarithm of cell A2. A fill up handle symbol will appear at the bottom right of the jail cell.  Figure ten shows an case of a fill handle symbol.  Identify the cursor over the make full handle.  The cursor will change from a white cantankerous to a blackness cross. If your cursor appears as a black cantankerous with arrows, reposition information technology over the fill handle until you run across a black cross.  Hold the left mouse button down and drag down column C until yous are in the same row as the final temperature value.  This should be cell C8.

When you release the mouse button, all the cells will fill up with the natural logarithm of each corresponding temperature value.  This is a quick and easy method to copy the same office into many cells but at the same time irresolute the reference cell.  The reference cell is the cell the formula uses for its input information in its adding.  The reference cell for prison cell C2 is prison cell A2. Notice how Excel copies the same formula from prison cell C2 to cell C3 but information technology changes the reference jail cell from A2 to A3. This is called a relative copy and continues downward the column if you lot employ the fill handle method.  Don't forget to check a few of the values in column C to ensure that Excel is making the correct calculations.

Figure 10 :  An example of a fill up handle on a selected prison cell.

• • The newly calculated information will likely take up to 10 digits recorded in the cells.   This is not the correct number of significant digits.  Each original temperature value contains three pregnant digits.  The result of a logarithm has the aforementioned number of significant digits to the right of the decimal every bit in that location are significant digits in the number whose logarithm is being calculated.  Thus, the logarithm of an original temperature value will take 3 significant digits to the correct of the decimal place. To alter the number of decimal points, highlight the data in cells C2 to C8.  Click the "Dwelling house" tab and then click on the decrease decimal icon (Figure 11) until the correct number of pregnant digits is present.

Figure xi : Location of the decrease decimal icon in the Dwelling tab.

• • Now nosotros want to graph the natural logarithm of the temperature versus the time of diffusion, fit the plot with a trendline and have excel summate the R ² value, but the time of diffusion values, which are in Column B, are on the left-paw-side of the natural logarithm of temperature values, which are in column C, and if we are use the same graphing method that we learned in Office 1, we need the time of diffusion values on the right-paw-side of the  natural logarithm of temperature values.

To remedy this, we can copy the time of diffusion values from column B and paste them into cavalcade D. To do this, highlight B2 to B8 by click and dragging the mouse, then select "Copy" and so select cell D2.  Select "Paste".  This will paste the time of diffusion data into cavalcade D.  Create a natural logarithm of the temperature versus the time of diffusion  with a best-fit-line and R ^two value.

4. Echo this procedure for the other two functions of temperature.  In the case of the foursquare root of the temperature, at that place are a couple of ways to enter the formula.  Commencement, Excel has a native or congenital-in part to calculate the square root of a value in a prison cell. The formula is "=SQRT(A2)", where SQRT() is the congenital-in part and A2 is the reference jail cell.  The office will render the square root of the value in cell A2.

Another method uses the power function. The formula to be entered is "=POWER(A2,0.v)", where Ability() is the formula, A2 is the reference prison cell and 0.5 is the ability to which the reference is raised.  Some other grade of the ability formula is "=A2^0.5", where the circumflex character ( ^) means "raised to the power of".

For the formula to calculate the inverse of the square root of the temperature there are a number of formulas: "=one/SQRT(A2)",  "=POWER(A2,-0.v)",  "=POWER(A2,−0.v)", =( A2)^(−0.5).  Once y'all have all the columns finished, complete the plots, fit a trendline and R ² values to the plots and make up one's mind which is the most linear.

5. Record on your report:
   • the R ^two value for each of the four graphs
   • Answer the questions: Which plot produces the most linear relationship? How do you know?
   • the equation of the trendline for the most linear plot. ? the gradient of the trendline for the most linear plot.

e) Include all graphs forth with the table of values that was used to create all four graphs .

Include this in your assignment as part of one document

For reference:  To print but the data and not the graphs, highlight all the data including titles and select "File" then "Print".  From the drib downward menu nether settings that currently says "Print Active Sheets", click on the downward pointer and select "Print Selection".   Then only the highlighted data should exist printed.

Part 3: 2 Data Sets with Overlay

Scenario: In a Beer'southward Law experiment, a spectrophotometer is used to measure the amount of light absorbed for ii different coloured nanoprisms.  The two sets of data collected are

presented in the table beneath.

Tabular array three: Concentration and Absorbance values for two Nanoprisms A and B.

You would like to meet how these two sets of data chronicle to each other.  To do this you volition have to place both sets of information, as contained relationships, on the aforementioned graph.  Superimposing plots is a viable option for presenting multiple sets of graphical data if the values of the dependent variables of the two sets of data are similar and if the values of the dependent variables of the two sets of information are similar.

1. Enter this new data on a new spreadsheet (Sheet 3) in Excel. Label your information columns with appropriate titles. Once again, think to enter the 10 values to the left of the y values.  Use the increase/decrease decimal icon to bear witness all meaning digits for the data.
2. First, plot Nanoprism A information every bit an xy- besprinkle plot.  Fit a trendline to this information using linear regression and obtain the equation of this line.
3. Now add together Nanoprism B information to this graph.
   • Actuate the graph by clicking on ane of the plotted information points.
   • Click on the "Design" tab and click on the "Select Data" icon.  The "Select Data Source" window should announced (Figure 12).

Figure 12 : Select Data Source window displaying for Canvas three.

• • Click the "Add together" tab (Effigy 12), and type "Nanoprism B" for the Serial Name (Effigy 13).
  • Click the collapse dialogue button, located just below and to the right of the "Series X values:" (Effigy xiii), This volition minimize the edit series dialogue box and change the collapse dialogue button to a expand dialogue button.
  • Select the values of concentration for nanoprism B (column C) with a click and elevate move of your mouse. Expand the Edit Series dialogue box by clicking on the expand dialogue button.
  • Select the collapse dialogue push button for the "Series Y values" and select the values of absorbance measurements for nanoprism B. Aggrandize the dialogue box by clicking on the expand dialogue button. Click on the "OK" button.  This will return you to the "Information Source" window. Clicking OK will close this window, plot the data for nanoprism B on the same graph as nanoprism A and return you to the main spreadsheet window.

 Edit Series window displayed for Nanoprism B Series.

3. • Click on the "Layout" tab, then "Legend" and choose to show the Legend at the right hand side instead of on the graph if information technology isn't already there.  To rename "Series one", click on the Legend box.   Correct click and then choose "Select Data".  Highlight "Series1" and and then click on "Edit".  The "Edit Serial" window will appear.  In the Serial Name box type "Nanoprism A".    Click "OK".  Click "OK" once again.   The fable should be updated to Nanoprisms A.
   • Fit a trendline to the data for nanoprisms B.
   • Nosotros want to remove two text boxes in the legend, namely, "Linear (Nanoprisms A)" and "Linear (Nanoprisms B)". Click on the legend, and so click one of the textboxes, press "delete" on the keyboard. Repeat these deportment for the other textbox.
   • Add an appropriate title and axis labels. Print this graph and adhere to the written report.
4. Record the following information on your written report:
   • the equation of the best-fit trendline for Nanoprism A.
   • the equation of the best-fit trendline for Nanoprism B.
   • attach a re-create of your graph (ensure large enough to run across points, line, etc.) Ensure y'all have proper significant digits in this equation of the line.

Part 4: Choosing the Correct Parameters for Graphing

Scenario: The following data was nerveless from an experiment which measures the rate constant (chiliad)  of a first order hydrolysis reaction as a function of temperature.

Table four: Temperature and Charge per unit abiding data for a get-go gild hydrolysis reaction.

Temperature (K)	Rate Constant, one thousand (s −i )
two.lxxx×10 2	4.70 × 10 −ii
2.85×10 2	vi.87 × ten −ii
two.90×x 2	nine.85 × 10 −two
2.95×10 two	1.41 × x −1
three.00×ten 2	ane.97 × ten −1

a)   The rate constant, k, and the temperature, T, are related via equation (ane):

−E a

	g =AeRT The parameter A is called the frequency factor, the units of which are identical to those of m (s −1 in this case), E a is the energy of activation (units of kJ/mol), and R is the thermodynamic gas constant (8.31 x 10 -3 kJ/Yard mol).  Since the human relationship between k and T is an exponential 1, the data set, when plotted, will non be linear.  Your goal is to mathematically transform Equation one from an exponential equation into a linear equation.	(1)
b)	How practise you have an exponential function and transform information technology into a linear part?  Well, you have to transform the exponential term into a linear term.  To do this, only take the natural logarithm of both sides of the equation and simplify.  This gives a new, equation (two) beneath. East lnk ln A a

= − RT Information technology is this office that y'all must plot to get a straight line.  But exactly what are you going to plot on the x axis and y axis to create this linear graph?  If you lot rearrange the previous equation, it might become evident (Equation 3).  Equation three is in the slope-intercept form of a straight line. Place y, x, m and b in Equation 3 and tape them on your report. E lnm a 1 ln A

(2)

=− ₍ ) +

R T (3)

3. Enter the information from Tabular array 4 into columns A and B on a bare spreadsheet (Sail 4) in Excel.
4. Is temperature office of the y-value or x-value in equation 3? Write a formula using Excel functions  to convert the temperature data from table 4 into values that will give a linear relationship every bit outlined in equation (three) and question (b).  Exist certain your new values have

the right number of significant digits.

5. Is the rate constant part of the y-value or ten-value in equation 3? Write a formula using Excel functions to convert the charge per unit constant information from table 4 into numbers that will give a linear relationship equally outlined in equation (iii) and question (b).  Exist sure your new values have the correct number of significant digits.
6. Plot these new calculated values to obtain a linear plot.  Fit a trendline to your data set and display the equation of the trendline and the R ² value with the correct number of pregnant figures.  The number format for the equation of the trendline is likely in "general" format and will not take the correct number of pregnant figures. In order to change this, double click on the box containing the equation for the trendline and R ² value.  The "Format Trendline Label" window should appear.  Click on "number" and then select the "Scientific" category with ii decimal places. Select "close".
7. Tape the equation of the trendline on your study with right pregnant digits.  Then employ information obtained from this equation to calculate:

? the value of Due east _a in kJ/mol. ? the value of A, in south ^-ane .

Record and bear witness your work with correct final number of significant digits for the calculations on the study.  Include the tabular array of the new calculated data and the actual plot in your assignment.

Role v: Statistical Assay

Scenario: A sample of water was analysed for sulfate ion (SO ₄ ^-2 )  concentration.  10 split up analyses were conducted.  The results of the analyses are presented in Table 5.

Table 5:  Sulfate ion concentration in ppm for water samples in lab #1 at WLU.

Assay #	1	2	3	iv	five	6	7	8	9	10
WLU Lab#1 (ppm)	35.nine	43.two	33. 5	35.ane	32.8	37.6	31.9	36. six	35.0	32.0

Elementary statistical analyses of this data set include determinations of the mean and median concentration, and the standard departure of the information set.  Both the hateful and median are measures of central tendency of the data, commonly referred to as the boilerplate.  Standard deviation is a measure of the amount of difference or variation in the data set.  Standard deviation is a measure of precision. A small standard deviation indicates a data set that tends to grouping closely together, while a big standard divergence indicates a information set that is spread out over a big range.

The mean or arithmetic hateful ( ¯ ¹⁰ ) is divers as the sum (?) of each of the measurements (x _i )  in a information fix divided by the number of measurements (N)  (equation  4):

∑ ten ⁱ

¯10=

Due north The median (M)  is the midpoint value of a numerically ordered data set, where half of the measurements are in a higher place the median and half are below.  The median location of N measurements (equation v) can be found using:

(4)

G =(Northward+1)/2 When N is an odd number, the formula yields an integer that represents the value corresponding to the median location in an ordered distribution of measurements.  For instance, in the gear up of numbers (three, 1, 5, 4, 9, nine, 8) the median location is (seven + ane) / 2, or the four thursday value.  When applied to the numerically ordered set (1, 3, four, 5, viii, 9, ix), the number 5 is the 4 thursday value and is thus the median – iii scores are above 5 and 3 are beneath 5.  Note that if there were merely 6 numbers in the set (i, 3, 4, 5, eight, ix), the median location is (6 + one) / two, or the 3.5 th value.  In this example the median is one-half-way between the 3 rd and iv th values in the ordered distribution, or 4.5. Standard deviation (s)  is a measure out of the variation in a data set, and is defined every bit the square root of the sum of squares divided by the number of measurements minus one (equation 6):

(5)

s

(vi)

To find s, subtract each measurement from the mean, square that result, add together it to the results of each other deviation squared, separate that sum past the number of measurements minus one, then take the square root of this upshot.  The larger the standard deviation, the greater the variation in the information and the lower the precision in the measurements.

We employ meaning arithmetics (pregnant figures rules) as a way to maintain significant digits when determining standard divergence. The standard difference and the average should both end at the same decimal place.  For example, if nosotros had determined that the boilerplate mark on a grade examination, marked to unit precision, was 72.36598 with a standard deviation of 7.22014, nosotros would express the class outcome as 72 (7), where 72 is the average, the standard deviation is reported in parenthesis, and both are reported to the same number of decimals.

 While the hateful, median and standard deviation can be calculated with a calculator, it is ofttimes more user-friendly to use a figurer to decide these values.  Microsoft Excel is particularly well suited for such statistical analyses, especially on big data sets.

1. Enter the data caused by the students from WLU #i into a unmarried column of cells, for case cells A2 through A11 (cell A1 holds the championship "WLU#ane"), on a new spreadsheet in Excel (sheet v).  Be sure to format the cells to provide one decimal place.  And so in an empty cell, ordinarily direct below the data cells, you will instruct the programme to perform the required functions on the data.

 To compute the mean:

• • Click on an empty cell beneath or to the correct of the numbers for which yous want to determine the mean.
  • On the Home tab, in the Editing grouping, click the pointer adjacent to "∑ AutoSum", a dropdown menu will announced, click "Boilerplate", and then press ENTER.  Alternatively, type "=Boilerplate(A2:A11)" and press ENTER .

To compute the median:

• • Click on an empty cell beneath or to the right of the numbers for which you want to determine the mean.
  • Type "=MEDIAN(A2:A11)" and printing ENTER .
  • Be certain the adding does non include the value for the mean.

To compute the standard deviation:

1. • Click on an empty prison cell beneath or to the right of the numbers for which you want to make up one's mind the mean.
   • Type "=STDEV(A2:A11)" and press ENTER .
   • Be sure the calculation does not include the value for the mean or median.
2. Tape on your study:
   • The Excel calculated hateful, median and standard deviation for the WLU#1 data set with the correct number of pregnant digits.

Rejecting Outliers

Exercise all the measurements in the WLU #1 data set look every bit skilful to yous, or are there any points that practise not seem to fit with the others?  If and so, is information technology appropriate to pass up these measurements?

Outliers are data points which lie far outside the range defined by the rest of the measurements and may skew your results to a bang-up extent.  If you lot make up one's mind that an outlier resulted from an obvious experimental error, for example you incorrectly read an instrument or incorrectly prepared a solution, you may decline the point without hesitation.  If, however, none of these errors are evident, you lot must use circumspection in making your decision to keep or reject a bespeak. One rough criterion for rejecting a data point is if information technology lies across ii standard deviations from the mean .

3. Using the criteria supplied higher up, make up one's mind if whatsoever measurements in the WLU #1 data set are outliers.
   • Record on your report which measurement(s), if whatever, are outliers.  Explain.
   • Then excluding the outlier(south), re-calculate the mean, median and standard deviation of this data set using Excel.

f)     Did the standard departure change between the original and re-calculated data?  If so, what does this represent for your recalculated data?  Reply on the report sheet.

Rejecting information points may not be done just because y'all want your data to expect better.  If you cull to reject an outlier for whatever reason, you must always clearly certificate in your lab report or on your data sheet:

• that you did turn down a point
• which point you rejected ? why y'all rejected it

Failure to disembalm this could constitute scientific fraud.

Adapted from:  Scholefield, Michelle. "Using Excel for Graphical Analysis of Information".

Chemistry 11 Lab Experiments.  Santa Monica College. CA. USA,  2007.

Name: Appointment Submitted: ID#:_________________________________     Lab Section:

ASSIGNMENT ane – To Excel in Chemistry

 Instructions :

Make full in the blanks using a PEN OR TYPED answers and submit all sheets and required graphs/tables just in I document to exist uploaded to your online CH110 Lab MyLS dropbox.  No other lab report criteria is required.

Part one: Simple Linear Plot

?	Which set of data is plotted on the y-axis?
	the ten-centrality?
?	Record the post-obit data:
	The equation of the fitted trendline

The value of the gradient of this line

The value of the y-intercept of this line

• Is the fit of the trendline to your data a good fit? (circle one)     Yeah / No Briefly explain your response:

• Determine the temperature, in Kelvin, of the gas in the cold room when it has a measured volume of 10.v L using:
  1. Extrapolating by graphical means
  2. Extrapolating by using the equation of the trendline

Prove your calculations for b) below:

• Include a printout of your graph to this written report.  Exist sure that your axes are properly labeled, with units, the equation of the line and the R ⁱⁱ value are visible, and that your graph has an advisable title.

• For the Time of Improvidence versus Temperature plot, why is time plotted on the y- axis?
• For the Time of Diffusion versus Temperature plot, which set of data is placed on the left in the Excel worksheet?
• What are the R ² values for the four graphs?  Fill-in the tabular array below.

	Time vs. Temperature	Time vs. ln(Temp)	Fourth dimension vs. (Temp) 0.5	Time vs. (Temp) −0.v
Rtwo

• Which plot of the four graphs produces the most linear human relationship?  How exercise yous know?
• Record the following data:

The equation of the trendline for the most linear plot

The value of the slope of this line

• Include a printout of your graphs to this report.  Be certain that your axes are properly labeled, with units, the equation of the line and the R ⁱⁱ value are visible, and that your graph has an appropriate title.
• Print the table of values that was used to create all iv plots.  Include units and pregnant digits as appropriate.

Part 3: Ii Data Sets and Overlay

• Tape the equations of the trendline fitted to the plot of:

Nanoprism A: Nanoprism B:

• Include a printout of your graph to this report.  Be sure that your axes and title are properly labeled, with units, the equation of the line, the R ² value and the updated fable are visible.

Part 4: Choosing Correct Parameters for Graphing

• Consider this equation which relates the rate constant (k)  of a hydrolysis reaction to temperature (T):

E ^{a ane}

lnthousand=− ₍ ) +ln A

R T

If this equation is in the gradient-intercept form of a line, which term in this equation corresponds to:

y?x? m?

b?

• Apply appropriate functions to manipulate the data in Table four and create a linear plot.  Record the equation of the trendline beneath. Adhere your table of values for the calculated data and your linear plot in your study.

Equation:                          _______

• Using the equation of the best-fit line determine a) and b) (run across below).  Show your complete work in the space provided.
  1. the value of E _a (in kJ/mol)
  2. the value of A (in s ^-1 )

Part 5: Statistical Analysis

• For the WLU#1 data set, record the post-obit values with units (adamant using Excel):

the hateful SO ₄ ^two- concentration the median So ₄ ^2- concentration the standard deviation in the data set

• Are in that location whatsoever outliers in the WLU#1 data prepare (circle one)?     Aye / No

If yes, which measurement(due south) are the outliers?

Evidence the calculations you lot used to identify the outlier(south).  If you determined that there were no outliers, explicate how you came to this conclusion.

• Re-calculate the post-obit values (using Excel) excluding the outlier(s) if appropriate:

the mean And then _iv ^-ii concentration the median So ₄ ^-2 concentration the standard deviation in the data set

• Did the standard departure modify betwixt the original and re-calculated data?  If so, what does this represent for your data?

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Source: https://helpinhomework.org/question/24916/CH110-ASSIGNMENT-To-Excel-in-Chemistry-Assignment-Instructions-Hand-in-the-fill-in-the-blanks-s

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