[mam2011]

A student was given a stock aluminumIII solution with a concentration of 5.000 ppm. The student prepared 5 100ml standard solution and an unknown.  The absorbance was read at 565nm using the blank to set zero absorbance.  The results are (ml of AlIII stock solution used) 8.00 and absorbance .557

Question Calculate the concentration of AlIIIi n ppm. I am just wondering if someone can please help me out with setting up this problem. I am not looking for the answer i am just confused on how to set it up.

[mam2011]

Is there anyone who can help me out with this please

[Arkcon]

Try to start solving by building a table:  what you have for a standard, what absorbance value you get, and see if you can put the problem together without so many words.

[mam2011]

So far i have

Solution                   mL of Al (III) stock used                Absorbance
1                                        8.00                                     0.557
2                                        6.00                                 .438
3                                       4.00                                      .306
4                                    2.00                                             .174
5                                      1.00                                  .318


THis is where i get confused because im not to sure where to go from here. I just need assistance with setting up the equation

[Arkcon]

Very good.  I saw some missing info in your first post, and we have it now.  OK, you want an equation, but before we start to get one, you might want to visualize your data.  Can you load it into Excel (or other computer spreadsheet) and generate a graph?  Doing that in Excel is better than doing it by hand, for reason that will become clear.