Im working on this lab for my chem 2 class, and I have to fit a smooth curved line to the data. Well as you can see below, the line goes so far and then stops. Ive been looking through the help index and google and I cant find where this problem is mentioned or how to fix it. The other 2 graphs are having the same problem too.
If someone could let me know whats going on it would save me a lot of time. thanks!!

 

Use a blue pen?

 

Can't you use the "fit(x1,y1;x2,y2)" function? That should give you the line of best fit ... ???

I hate Excel to do scientific graphs... there's a program called "Origin" that does all the scientific graphing easily. (This was during my Windows 3.1 days when I had to do graphs like this ... )

http://www.originlab.com/index.aspx?s=12&lm=62

Apparently, this company still exists!

 

This may seem like a weird answer, but if you are sure you've set everything up correctly and it's just not showing up on screen, go to Print Preview or some other *view* of the graph, and see if it shows up then.

Lately I've noticed some of my MS Office products don't *always* depict the programmed changes on screen and I've had to do some work to figure that out. Hope that helps (but I doubt it will)!

 

Im a noob at excel. I wouldnt know how to implement the function you just mentioned.

Im just wondering if someone knows why the line stops there instead of going through all the points like its supposed to.

 

yeah i thought that too.. i even saved the program to a flash drive and loaded it on another computer to make sure my computer wasnt acting funny. its like that on the other computer too

 

Just so we're clear, are you trying to just connect the points or are you trying to find a best fit curve?

If you're just trying to connect the points, you need to switch from a scatter plot to a scatter plot with lines.

If you're trying to do a best fit line, right-click on one of the data points and select "Add Trendline." Then select the appropriate type trend line and make sure to display the formula and the r-squared value as needed.

Btw, looks like you're plotting the concentration of a chemical. What type of experiement was it?

 

I would make sure the entire series is selected before you add the trendline

 

It is a scatter plot with a line. I figured it out though. Because there are four solutions, my table looks like this..

And im only graphing solution 1 right now, so the first 9 points show up and then because of the blank cells the line stops.

This isnt a trendline, just a smooth fit curve xy scatter plot
0
2 0.642
4 0.593
6 0.538
8 0.478
10 0.428
12 0.387
14 0.347
16 0.307
18 0.277
20
22
24
26 0.19
28
30
32
34 0.132
36
38
40
42 0.094
44
46
48
50 0.059
52
54
56
58 0.038
60
62
64
66 0.02
68
70
72
74 0.011
76
78
80
82 0.003
84
86
88
90 0

 

did you right-click a point on the graph and select "trendline"? try that

 

^^ sorry...my bad..i had my reply open but diddnt submit it for like 10 minutes...lol i'm at work

 

Lol

 

well.. it appears from the data you provided that in some cases you dont have two data points therefore excel cannot connect an x to a y because only one is present.
Look at the data you provided. if you count 9 numbers down to "20" there is no other value, unless it takes on the same value as the value you got for number 8

 

exactly im not sure how to fix that because I cant just delete that blank cell, because even though that y value doesnt exist for that solution, there are other solutions that do have a y value for that x.
If I delete that x, i delete a y from another one of my solutions.

if that makes sense. hard to describe online.

Ive somehow got to get excel to ignore the blank cells.. which is where my noobness comes in

 

because we alternated measuring the solutions every 8 minutes

 

Were determining the rate law of Cr-EDTA

 

then your x value for time should be in 8 minute intervals that way you have conitinuous data points that correspond with one another try that

 

Here's what you need to do:

You need to set up each series seperately with different x-values.

So go ahead and reorganize your data so that the x-values that appear for the first solution are only the ones with corresponding y-values. Then repeat for the second solution and so on.

Then, when you start to graph, only select the data for the first solution and start the graph. Once you've created the graph, go to the graph and right-click, then select "Source Data." Click on the "Series" tab and then click on the button under the sample graph that says "Add." Now you can add the data from the second solution with its own independent x-values and y-values. Repeat the add for the other solutions as needed.

 

^ Excel god ...

Hint, Sylvia ... use a logarithmic scale as the Y-axis ... it'll be a straight line afterwards ...

 

The option you are looking for is called "interpolated". It plots the data while skipping the blanks. not sure if this works on a scatter chart though, i cant test it at home since i dont have excel here