Aluminum Ion Detection with AAS: Can 0.00014% Al 3+ be Detected?

[14h54]

Hi, I need help with a question on my lab worksheet.

Homework Statement

A solution is 0.00014% in Al 3+ ion. The detection limit for aluminum ion is 2 mg/L using AAS. Would the aluminum ion in this solution be detected by AAS?

Homework Equations

1 mg/L = 1 mg/1000mL which corresponds to 1 mg/1000g

The Attempt at a Solution

I feel like 0.00014% of Al 3+ means 0.0037772g of Al 3+ (0.00014*26.98g/mol). I then have to compare that to going from 2 mg/L to some percentage? We didn't do any calculations in lab other than finding the volume for Pb 2+ & HNO3 needed for our specified ppm.

I honestly have no clue how to go about this.


Thank you for the help.

 

[Jack the Stri]

Usually, when a concentration is described in a percentage it means w/v or w/w, not molarity. So all you have to do is figure out w/v or w/w (which are practically equal here), and see how it compares to 2 mg/l.

 

[14h54]

What do you mean by w/v or w/w?

 

[Jack the Stri]

Weight per volume or weight per weight.

 

[14h54]

So 0.00014% would mean 1.4E-7g per .1 L?
And I would then have to covert 2 mg/L to g/L and compare?

 

[Jack the Stri]

It equates to 0.00014g/0.1l, so 0.0014g/l or 1.4 mg/l, if I'm not mistaken.

 

[14h54]

I see now.

And thus the answer would be yes.

Thank you for your help.