I would like you to "push" my solution as I am bit stuck there.Problem:
Standard solution is made and contains the following data:
0.5021 g ethyl propanoate
0.4927 g propyl ethanoate
4.7243 g acetone (solvent)
The standard solution and the sample are run twice each and the following results are obtained:
Component 1 Determ. 2 Determ. Average of 2 determ.
Ethyl propanoate 525 521 523
Propyl ethanoate 492 487 489.5Sample
Ethyl propanoate 472 474 473
Propyl ethanoate 380 376 378
Use the external standard method to calculate the content of w/w% ethyl propanoate anw w/w% propyl ethanoate in the sample. Your calculations must be included.My solution:
1) At first I found average of two determinations
2) I can assume that the volume is 1 L
So C of the standards:
C(ethyl propanoate) = 502.1 mg/L
C(propyl ethanoate) = 492.7 mg/L
3) Calculation of C
sample in external standard method is:
C(x) = C(st) * (A(x) / A(st))
so I am calculating concentration of my sample:
C(ethyl propanoate) = 502.1 * (473 / 523) = 454.1 mg/L
C(propyl ethanoate) = 380.5 mg/L
4) w/w% ethyl propanoate anw w/w% propyl ethanoate in the sample.
And here I am stucked. Should I do something with solvent?
Thanks in advance!