Lab question (Chem)

[Ninjakat]

The problem with online learning is they give you nothing to work with except questions. I did absolutely nothing on this topic so some help would be nice.

 

Design a laboratory set-up that would enable you to separate a mixture of three hydrocarbons with different boiling points. Explain the reasons for the apparatus you would need in your set-up, and develop the procedure you will use to separate the hydrocarbons. You should also include a blank data table for recording results. (Note: You are not going to perform the actual experiment, so do no report any results)

[cypress]

The problem statement gives you a clue. How can you exploit the differences in boiling points? What does boiling point differences imply about partial pressures?

[mississippichem]

The problem statement gives you a clue. How can you exploit the differences in boiling points? What does boiling point differences imply about partial pressures?

 

Yes, Cypress gives good advice. Also in your answer, you might discuss the correlation between boiling point/vapor pressure and molecular weight.

[Ninjakat]

Well at different boiling points makes it evaporate.

 

So for 3 hydrocarbons would you do 3 different experiments?

 

Each one recording the vapour at different boiling points?

[Fuzzwood]

Does the term destillation mean anything to you?

[cypress]

What you propose might be an interesting thing to do, but don't lose sight of the stated goal. Your challenge is to separate these three hydrocarbon compounds. So....

 

Not three different experiments, but if you were to start with cold fluid and slowly heat it to near the boiling point of the lowest boiling hydrocarbon, what would be the relative concentrations of the three compounds in the vapor vs. the fluid?

[Ninjakat]

I did a lab for destillation online but it was with crude oil.

 

3 hydrocarbons im unsure how I'd do the same lab with more then one material?

[skyhook]

I think it is fractional distillation. like oil refinery. wikipedia have it. You can tap out the hydrocarbons at 3 different parts of a column-like structure.

[cypress]

I did a lab for destillation online but it was with crude oil.

 

3 hydrocarbons im unsure how I'd do the same lab with more then one material?

 

Crude oil is a solution/mixture of many (generally 30+) hydrocarbons. Separating just three is a much simpler task. Are you familiar with how a fractionation column (like for example a crude unit) works? Are you aware of how differences in partial pressures at different temperatures and pressures influence changes in relative concentrations? Do you think it would be practical to set up a multistage fractionator in a lab environment?

 

If not, perhaps you could design a batch unit similar to a moonshine(backyard alcohol distillation) still and design a proceedure to do it in stages. I am trying to be vague since I am not anxious to do your homework for you.

[Ninjakat]

No I dont know any of that. This is just college level grade 12 chem and they didnt cover anything else. Other then how to draw hydrocarbons and what is in them.

 

So please I really need help with this I dont want complex answers this is college level. I dont understand when you guys talk all "university" level.. like I need someone to BREAK it down into simple language and tell me what To do for this. I don't know much at all.

[Mr Skeptic]

OK, nice and simple: they boil at different temperatures, and after they boil they can be condensed so you get it back.