Homework Help: Chemistry

Posted by Mae on Monday, March 5, 2012 at 4:05am.

It is possible, although less accurate, to do a standard addition with only one sample. An unknown Fe sample was analyzed by AAS and gave an absorbance reading of 0.160. To the same sample we added 1.5ppm Fe and the new absorbance reading was 0.205. Calculate the ppm of the unknown Fe.

Could someone please explain to me on how to do this question step by step. Thanks.

Chemistry - L.Bianchessi, Monday, March 5, 2012 at 5:18am
You could probably set up a proportion.

so....
0.160/x= 0.205/1.5ppm
Solve for x.
Chemistry - DrBob222, Monday, March 5, 2012 at 3:48pm
I agree it probably can be done with a proportion; however, I wouldn't set up the proportion that way.
0.160 is for x
0.205 is not for 1.5 ppm but for 1.5 ppm+xppm.
(0.160/x) = (0.205/1.5+x) and solve for x.

Another way.
0.205 = 1.5 + x
0.160 = ......x
-----------
0.045absorbance due to 1.5 ppm
Then 1.5 ppm x 0.160/0.045 = ?

Answer this Question

Related Questions

Chemistry - It is possible, although less accurate, to do a standard addition ...
ap chemistry - A mixture contains only NaCl and Fe(NO3)3. A .456 gram sample of ...
Chemistry - A student is given a sample in lab which contains one of the ions ...
Chemistry - A student is given a sample in lab which contains one of the ions ...
gre math prob of a sample - sample standard deviation = 3 sample mean = 68 n=30 ...
chemistry - if the ration of water drops to EDTA is 6.7 for the known sample and...
Chemistry - If I am given that an unknown sample containing iron(II)ion is .949 ...
Sample purity - Question: A student spots an unknown sample on a TLC plate and ...
Statistics - An educator wants to estimate the proportion of school children in ...
Chemistry - A mixture contains only NaCl and Fe(NO3). A 0.456g sample of the ...

For Further Reading

First Name:
School Subject:
Answer: