[hope35]

So I did this experiment where I add two solvents together. One is [CoW₁₂O₄₀] and the other is [SCN]-. Both are in 1M NaNO₃. The concentration of [SCN]- varies. From 0.004,0.006, 0.008, and 0.012. So I added two mL of [SCN] and  [CoW₁₂O₄₀] and took the absorbance every 20 seconds. Did it once with each concentration. And I plot the data I'm suppose to somehow determine the order of reaction with respect to [SCN]-. How are you suppose to get this??

Also, I took the Absorbance at infinity by heating the solution. Not sure if that's need

[Borek]

Do you know absorbance of what you have been measuring?

[ironman2538]

Wht you have done is kinda look to me like determining the order of reaction using different intial concentrations.....You definately would need T_infinity as thts one of the term involved in the calculation...read any basic book will tell you how to use that data....
However you should know wht you are measuring the absorbance of.....as Borek correctly said....!!!!!
once you know you can put the graphs either as product Vs time or Reactant Vs time and you can find out the rate of the reaction....
after knowing rate of the reaction...Vs different intial concentrations you can put these values in eqn to fine 'n' that is order of reaction...
hope that helps..!!!!!

[hope35]

Thanks for  the info guys. I remember something about using an equation, but forgot which one was it. Can one you tell me what's it call or write the equation please?

Much Appreciated.

[ironman2538]

This is one of the page i got on google..
http://laude.cm.utexas.edu/courses/ch302/others/order.pdf

try typing on google like.....How to determine order of reaction.... you should get ton of papers..
Hope that would help..!!!!

[hope35]

k, thanks. One more thing. This may sound vague, but is there a reason why we take A_infinity?? In this case, we heat the solution for 20 min and took the absorbance reading again. I kinda remember doing an experiment where I took this reading, and kinda used that number in a equation. Does anyone have any idea?

[ironman2538]

A_infinity is nothing but the max reaction and thus the absorbance at the completion of the reaction. Basically that is required for the T_infinity. This value would be used as the benchmark in your reaction table to subtract the individual values of absorbances..!!!! I hope u have solved the prob by now completely./.!!!! Have fun n njoy kinetics....!!!!