The Periodic Table

Thing is we have to apply for funding. But I would if I already could ;)

skullpetrol

I see :-)

1:05 AM

Hello

Guys how would you go about converting 2bromopropanoic acid to ethanol?

Selling the acid and buying the ethanol is probably the most cost-efficient solution (even if this comment sounds trolly).

Hi @Ramanujan o/ and @Wdoctor123 o/

My first (chemical) ideas circle around generating pyruvate (turn Br into OH, then oxidise) and decarboxylating that; if need be using pyruvate decarboxylase. Then that can be reduced to ethanol.

I just want to know the process :)

so turn 2 bromopropanoic acid to 2 hydroxy propanoic acid using naoh

any ideas? :P

wait can I use the soda lime to decarboxylate to propanbromide?

Hydrochloric acid is kept in plastic or glass bottles, why?

@Jan May I suggest, an esterification with $\ce{EtOH, H+}$ to form ethyl 2-bromopropanoate, followed by a hydrolysis and isolation of the ethanol product?

1:20 AM

@orthocresol what would be the actual steps?

@orthocresol No, that is basically the selling and rebuying method ;p

@Ramanujan Whatever you have available, it doesn’t matter.

B-b-but it's a chemical reaction...

But none of the reactant’s carbon molecules make it to the final product …

@Jan,why?!?!?

@orthocresol Is that a chemistry version of the barometer question? ;-)

1:23 AM

@Loong Yeah, pretty much :D

@Loong What’s the barometer question?

@Ramanujan Well, you obviously don’t want to keep it in your bare hands, so you need a bottle …

Barometer question

The barometer question is an example of an incorrectly designed examination question demonstrating functional fixedness that causes a moral dilemma for the examiner. In its classic form, popularized by American test designer professor Alexander Calandra (1911–2006), the question asked the student to "show how it is possible to determine the height of a tall building with the aid of a barometer." The examiner was confident that there was one, and only one, correct answer, which is through calculating the difference in pressure at the top and bottom of the building. Contrary to the examiner's...

chemguide.co.uk/organicprops/acids/decarbox.html

wait so you can use the soda lime to get rid of cooh

@Jan, that's not the scientific reason..

so ch3chbrcooh + NaOh -> Ch3ch2br

ch3ch2br + naoh (heat and boil under reflux) -> ch3ch2oh

done

I think

Is this ok? or

is it wrong?

@Ramanujan because hcl doesn't react with plastic or glass

some plastics*

1:30 AM

@Wdoctor123 That would work, yes.

yay

@Ramanujan HCl doesnt react with glass or plastic; but if you want ultrapure hydrochloric acid, you should use plastic.

why plastic for ultra pure?

surely if you want the ultra pure you just make it on the spot?

Q: Can someone tell me how to solve this problem on enthalpy?

0

When 14.9 g of solid KCl is dissolved in large excess of water , the amount of heat liberated is 3.72 kJ. How do we calculate the heat of solution of KCl? You don't need to solve the entire sum just tell me what am I supposed to do with the mass?Will the reaction be KCl + H2O=K+ + Cl- ?

thermodynamics enthalpy

@Wdoctor123 Because the acid can leach trace metal ions from the glass.

1:34 AM

this should be easy.But I have no idea how to do it.Please help.

But if you have water in glass bottles, you practically always leach sodium ions anyway, don’t you?

(At least that was the explanation I was offered for why we always observe [M+Na]+ in MS)

But that's a good thing! Imagine all those positive ions!

@Matix What kind of result do you expect? An enthalpy in kJ/mol?

@Loong yes

@Jan Yes. And If you use ordinary acids for ICP/MS, you can see half of the periodic table.

1:38 AM

@Loong Do we need an equation?

The other half is shy.

@Matix ok, now how do you get "something per mole" from "14.9 g KCl"?

@Loong divide it by the molecular mass

@Matix aha

its 0.2 moles

1:41 AM

ok

@Loong how will that help?

so 3.72 kJ are released when you dissolve 0.2 mol KCl

yes

and 3.72 kJ/0.2 mol = ?

18.6

1:44 AM

@Matix unit?

that is the answer but can you explain??

kJ/mol

why are we dividing 3.72 by 0.2?

The literature value in the CRC Handbook is 17.22 kJ/mol.

@Loong What does that mean?

@Matix You wanted a result in kJ/mol, i.e. a molar enthalpy. Your experimental value was only an enthalpy in kJ.

oh

Thank you for helping.

1:48 AM

@Matix That means that your result has the correct order of magnitude.

Should I delete the question?

Q: Predicting the major product formed on reaction with silver

It is a homework question and could be closed if you don't show some of your own efforts in the question. Maybe you could even try to write an answer yourself now?

Bounty Hunter

3:12 AM

4

I am facing trouble with finding out the major product when 1-(chloro(cyclohexyl)methyl)cyclopropan-1-ol is treated with silver ions: My attempt was that in presence of $\ce{Ag^+}$ the three membered ring will open forming a ketone with chlorine atom in the $\alpha$ position. Then I thought t...

organic-chemistry reaction-mechanism

Martin - マーチン

6:27 AM

6:55 AM

@Loong ___

Morning all

skill patrol

o/

9:12 AM

@orthocresol the funniest part about this is I've seen it twice

Q: FIND THE PERCENTAGE OF NATURALLY OCCURING ISOTOPES

12:00 PM

-2

ITS URGENT EXAMS ARE COMING . IDON'T KNOW HOW TO FIND THE PERCENTAGE OF ANY ISOTOPES PLS HELP ME

ions atoms molecules

Question of the day

Isn't it also a dupe?

@Loong Aw shucks. It would've gotten to HNQ.

Only if you write a corresponding answer of the day.

Also I'm not sure if we can dupe something of an on-hold question.

@Loong I guess you can't even write a stellar answer to that no matter how much irrelevant/interesting info you put there

Q: How should we represent two bonded molecules of H_20?

EXAMS ARE COMING, BRACE YOURSELVES!

Martin - マーチン

12:45 PM

0

Should we represent it like this- 2 (H_20) or should we represent it like this - (H_20) _2?

discussion

CV pls ;)

1,3-feeds

1:05 PM

0

Q: How to handle this Li Zhi guy?

Most who have spent a considerable amount of time on Chem.SE this past year knows Li Zhi. visits on a biweekly or monthly basis: Li Zhi, et al, et al, et al, et al, et al, et al ... quality of the content of answer varies, but is sometimes alright formatting quality is terrible They never us...

discussion editing new-users

user123733

Among the following which will give tribromo derivative with bromine water

I think it should be 1) or 4)

Can somebody help me in this