Question

has anyone done this lab?
http://assets.openstudy.com/updates/attachments/527ef484e4b07e6b19115df1-sarahi_smiles-1384216314828-measuringmasscalculatingmoleslab.docx

Answer 1

There you go.

Answer 2

But what is the specific problem?

Answer 3

i dont know how to do the lab

Answer 4

Well obviously you need to weight something and then you can calculate the amount of substance in mol.

Answer 5

yea i have no clue how to do that

Answer 6

Let me take an example of something which is NOT on the list:
Lets take the the coenzyme biotin (also known as vitamin H):
Lets say we put this on a teaspoon and get that it weights 2.5 mg.
We now want to determine the molar weight of biotin. It's chemical composition is:
C10H16N2O3S:
So we get that:
\[M(C_{10}H_{16}N_{2}O_{3}S)=10 \times M(C)+16 \times M(H)+2 \times M(N)+ 3 \times M(O) + M(S)\]
All the data is found the periodic table.
I fast calculated it to:
\[M(C_{10}H_{16}N_{2}O_{3}S)= 244 g/mol\]
the amount of substance in mol is then given by:
\[n(C_{10}H_{16}N_{2}O_{3}S)=\frac{ m(C_{10}H_{16}N_{2}O_{3}S) }{ M(C_{10}H_{16}N_{2}O_{3}S) }\]
\[n(C_{10}H_{16}N_{2}O_{3}S)=\frac{ 2.5 \times 10^{-3} g }{ 244 g/mol }=1.0 \times 10^{-5} mol\]
Get the drift so far?

Answer 7

not at all that looks lie a bunch of random to me

Answer 8

Okay. Do you know what "1 mol" is?