# AS Moles HelpWatch

#1
Hi, I was quite stuck with this question on moles in my chemistry homework.

A toxic metal was released into a river killing many fish. Analysis of a dead fish showed it to contain 0.2 ppm (parts per million I think) (by Mass) of toxic metal in every 200g of dead fish. The relative atomic mass of the toxic metal is 112. Calculate the number of atoms of toxic metal in 10g of the dead fish.

I tried first:

0.02 ppm: 200g of dead fish so 0.01ppm: 10 g of dead fish.

Moles=[0.01/1000000]/112[Ar] so

Number of atoms = the above sum x by avagadro's constantwhich equals 5.4 x 10to the power 13.

Is this at all right or have I gone completely wrong?
0
9 years ago
#2
(Original post by t3h_y0u553f)
0.2 ppm (parts per million I think)
I need to know what the units of this are before I can work it out. parts per million of what? I don't understand...
0
#3
(Original post by sil3nt_cha0s)
I need to know what the units of this are before I can work it out. parts per million of what? I don't understand...
All it says is parts per million (by Mass)!

I've handed it in now anyway.
0
9 years ago
#4
(Original post by sil3nt_cha0s)
I need to know what the units of this are before I can work it out. parts per million of what? I don't understand...
1 ppm = 1 mg/L
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