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/sci/ - Science & Math

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4464635 No.4464635 [Reply] [Original]

Okay /sci/ I need someone to save me on this organic chem lab.

My ex cheated on me last week, so this lab is 1 week late. I was busy dealing with drama and couldn't sleep so I couldn't think straight. Now I forgot about the lab. Don't hate on me too hard.

We put a 50:50 1.5 mL Hexane/Toluene mixture into a distillation apparatus and heated it in an aluminum block at 90-100C. The BP of Hexane is 69 C and the BP of Toluene is 111C. A distillate was collected, and the remainder was left in a 3.0 mL vial.

The distillate is most hexane right? We injected it into a Gas Chromotography machine. The distillate first, the, then the stuff left in the vial. The first GC run (Distillate) had a HUGE first peak. Area % = 79% peak one. and a tiny second peak, 21% peak 2.

. The second GC Run (Remainder of the 50:50 solution) had about even peaks, the first peak being higher. First peak being 37.7% area, second peak being 62.3% area.

Would the first peak be hexane and the next peak be toluene? How would I determine the % hexane (molar) and hexane % by volume using calculations? I thought it was just the percentages spit out of the GC machine.

>> No.4464647

Bump

>> No.4464661

Bump again

>> No.4464670

>ex gf
>rules of sci.jpg

also, you can google this shit and youre a ruhtard for not knowing it in the first place

>> No.4464672
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4464672

No idea, son, failed every chem test I ever had, but DAMN those tits are beautiful! Bumping for you. simply for supplying big-boobed red-head.

>> No.4464675

>>4464670
Can you help me for being a retard?

I honestly can't figure it out, tried google fu.

>> No.4464686

I would suspect the first peak being hexane yes. You can be sure by injecting pure hexane and see what retention time it has. What are the parameters of the column? Wich would you think comes out first?
To know the concentration I think you have to make a calibration curve.

>> No.4464687

>>4464672
I support this comment.

>> No.4464699
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4464699

>>4464635
Her hotness kills me inside, by magnifying the fact that I don't have a girl like her...

>> No.4464704

You should get mostly hexane in your distillate, and mostly toluene in your remainder. This is true of your results.
Molar percentage = (mols reactant/mols total)x100.
You need to look up values of density for hexane and toluene.

>> No.4464721

>>4464699
thanks for the frog xD

>> No.4464730
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4464730

>>4464721
You laughing at my misery?