Recent content by oxshannon

Okay so is this correct? y = 0.0558x + 0.1946 absorbance = 0.0558x * concentration + 0.1946 absorbance - 0.1946 = concentration 0.0558 So then I plug the value 0.230 for absorbance into this formula, and solve, getting 0.6344 ppm?

Coolio. X intercept or Y intercept

Okay great. So I just have a couple more questions...how do I go about finding the slope of the line? And since that last section is wrong, how would I determine Cd concentration?

oh sorry I didn't realize you had to. Okay well here:

So then is this answer not right? http://www.cramster.com/answers-sep-11/chemistry/standard-addition-plot-concentration-cadmium-seawater-determind-sp_1491656.aspx?rec=0" I really am 100% lost and my book isn't helping at all. Ugh.

Right, ok so once I get the data points, I can plot this in Excel. But then how do I determine the concentration of Cd in seawater? Because wouldn't that be found using the equation slope of the line/(molar absorptivity * cell length)?Also.. are you taking into consideration that this is 6...

Any chance you'd like to elaborate on that? The stuff in my notes doesn't correspond to what you just said, there's a ton of stuff about dilution factors and what not.. http://science.widener.edu/svb/mathcad/pdf_docs/std_addition.pdf"

Homework Statement The concentration of cadmium in seawater can be determind spectrophotometrically. To six 50.0mL seawater samples, various volumes of a 10.0ppm cadmium solution were added and all were taken through the analytical procedure with the following results: Amount Cd Added...

Actually -- would it be possible to simply use Grubb's test?

Thanks a lot! It was the second day of classes (terrible time to come down with the flu), and I don't know anyone in the class, the professor just e-mailed me the assignment and still wants me to hand it in on time without notes. That's another story though. It's an analytical chemistry...

Anyone? :( I'm super desperate

thank you! i can't really find anything in my textbook, and the only reason I am unsure on how to do this is because i was really sick for the class so i didnt get to go, but I am still required to pass the assignment in, so I am legit lost :(

Homework Statement The following data were obtained for the analysis of soil for vanadium content in mg/g using two different methods. Do the two methods yield essentially the same results? Method 1 Method 2 26.30 26.22 26.43 26.32 26.28 26.20 26.19...

Homework Statement The following set of analyses represent concentrations of chloride in blood serum (meq/L): 103,106,107,114. One value appears suspect. Determine if it can be rejected at the 95% confidence level. Homework Equations Mean Standard Deviation...