[Dzoni]

I have an a$$hole of a design lecturer who gave us an assignment without giving us the properties of the chemicals involved. Now, I'm more than happy to go looking for these properties, but the chemicals themselves are really uncommon and I can't find info for the energy balance anywhere (and yes, I have looked through Perry's)!

I need to find the C_p and enthalpy of formation of the following:

- Dodecene (C₁₂H₂₄)
- Dodecylbenzene (C₆H₅.C₁₂H₂₅)

If anyone can help or point me in the right direction, it'd be much appreciated!

[xiankai]

u could look up the CRC handbook of chemistry and physics in a library, its most likely to have the data you are looking for.

you could also look up the MSDS of the compounds you named, and a source of some can be found via 'Search MSDS' on the left of the forum, under the subheading 'resources'.

[Dzoni]

Thanks for the swift reply, xiankai! I just checked the online catalogue of my University's libraries, and a number of them do indeed have the CRC Handbook of Chemistry and Physics, and seeing as I have some time to kill tomorrow, I'll definitely be checking that out!

I gave the MSDS a shot, with little luck, but I did find the b.p. of dodecene at 1 atm, which could very well prove useful!

[Donaldson Tan]

We have a relevant thread in this forum: http://www.chemicalforums.com/index.php?topic=8780

Please do a topic search in future instead of lamenting first.

[Dzoni]

Already done that, Geodome - sorry, should have mentioned I'd checked that thread... Didn't find any useful info. A lot of them have some of the properties of the substances in question, but list the ones I need as "not available", or have data for the gas phase, but not the liquid (which is what I need). OK, truth be told, there are too many sites to check out, but I did have a look at quite a number.

[Dzoni]

OK, so I've checked the CRC Handbook (thanks again, xiankai), and found the required values for dodecene. Dodecyl benzene, however, is nowhere to be found... Any further suggestions?

As a last resort, I could estimate the values at http://pirika.com/chem/TCPEE/TCPE.htm. However, it'll only estimate the C_p as a gas. Is there any way of relating/estimating the liquid's C_p based on that of the gas of the same species?

I don't like the idea of making an estimate of an estimate, but at this stage, I need something to work with, and an estimate is better nothing!

[Donaldson Tan]

Do you have a project supervisor whom you can approach where to establish the data source?

If your lecturer gives you this assignment, I am sure he and his post-graduate assistants know where to get this data.

[Dzoni]

He doesn't have any post-grad assistants (oddly enough), and I've spoken to him about what to do - the reply was along the lines of "I don't care, it's your problem". As I said, this guy is a bastard of note, who revels in making our lives difficult. In fact, he handed out some photocopies from a textbook to us, and while he was reading through it, he decided then and there to make it our assignment, without having any idea whether there was enough info or whether that info was realistically obtainable. Oh well, I'm not gonna mope around because of that... While Perry's doesn't have the actual values, I think it might have something on estimating C_p, so I'll hit the library tomorrow to check it out.

[Donaldson Tan]

I've spoken to him about what to do - the reply was along the lines of "I don't care, it's your problem". As I said, this guy is a bastard of note, who revels in making our lives difficult.

No wonder he does not have any post-graduate assistants.. He would make their lives difficult too. If you get a copy of that textbook, you might actually find the information you need.

[Dzoni]

Hehe, tried that already... It was the first thing I did, actually - "Plant Design & Economics for Chemical Engineers" by Peters & Timmerhaus. Nothing - the reason being that it was simply an example to illustrate what the preliminary design calculations might look like, i.e., it was not actually meant to be done by the reader.

HOWEVER, Perry's does indeed have a method of estimating C_p's of liquids to within 6%, which means that I now have enough, more-or-less correct information, to finish the damn energy balance! Hooray!

Good news for me (apart from finding the value), is that this lecturer is leaving at the end of March. Hopefully he'll be replaced by someone decent!

Thanks for all the suggestions, Geodome and xiankai.

[mbeychok]

Dzoni and all others:

Everyone should get familiar with using this website of the "NIST Chemistry WebBook":

http://webbook.nist.gov/chemistry/

NIST is the National Institute of Science and Technology. I am amazed that no one mentioned using this website.

[Dzoni]

Had a look there as well, mbeychok... No luck!

[mbeychok]

Dzoni:

You are correct, the NIST ChemistryWebBook has some, but not much, data on dodecylbenzene. However, it does give these synonyms for dodecylbenzene:

Dodecane, 1-phenyl-
n-Dodecylbenzene
Laurylbenzene
Dodecane, phenyl-
Phenyldodecane

Perhaps, a Google search for those names might prove fruitful.

[Dzoni]

mbeychok:

Yup, I've already tried the synonyms (found them at http://www.cheric.org/research/kdb/hcprop/showprop.php?cmpid=716) both on Google and in the CRC Handbook of Chemistry & Physics. Much like with the other attempts, no luck.

Thanks, anyway!