[naranja]

The lab is determining the amount of copper in a tablet using AA spec. I've made my calibration curve and calculated a value of 2.48ppm for the tablet. The tablet was diluted in 100ml of 'extraction reagent'.

The question is to calculate the mass of copper in the tablet.

I don't even know where to begin.

Can anyone shed some light please?

[Burner]

'2.48ppm' is the concentration of copper in the reagent. 1ppm = 10^-4% by mass.

[naranja]

so for 2.48ppm x 10-4 = 0.000248?

i understand ppm is the concentration. and i was thinking using the cv = mol then multiplying mol by Mr of copper to get the mass in grams. but I'm not sure which values to use

[Hunter2]

ppm stands for part per million. In other words 1 mg per 1kg or 0,001 g/1000 g

2,48 ppm is 2,48 mg/kg, sometime with specific gravety = 1 g/cm³ also 2,48 mg/l

[naranja]

so do i just divide 2.48 by 100ml then multiply by Mr of Cu.

sorry I'm not getting it.   

[AWK]

so do i just divide 2.48 by 100ml then multiply by Mr of Cu.

sorry I'm not getting it.   

ppm and % concentrations do not need multiplying by atomic mas of copper for calculation of its mass. Also, use definition of concentrations correc tly.

[Borek]

ppm is not much different from % concentration. Actually % is the same thing as pph - parts per hundred.

If you were told concentration of your sample is 2.48% and its mass is 100 g, how would you find the mass of the solute?

[naranja]

(x/100) . (2.48/100) ?

[naranja]

an attempt of mine is...

0.1L from 100ml

(2.48/10⁶) x (x/0.1L) = 2.48 x 10^-7kg

so 2.48 x 10^-4g??

[Hunter2]

Yes or easier 0,248 mg in 100 ml.