Thread: Chemistry Game

Ok for anyone who reads the math subforum you know they have a forum game going on where people pose maths questions to eachother and the rest of the forum has to get the answer.
I think this is a cool idea as it gets you thinking and imo doing problems are the best way to learn, (anyone who has tried to read a fluid mechanics textbook will vouch for this).

So I am proposing a game for the chemistry forum where people have to work out what chemical X is from given information, first person to guess posts information on a new chemical X.

So I will give the first question as an example.

Compound X is a Colourless Organic liquid, with a pungent fruity smell.
X gives a yellow/orange precipitate on reaction with 2-4-Dinitrophenylhydrasine.
on reaction with iodine and sodium hydroxide. X yields a pale yellow precipitate with an antiseptic smell.
When reacted with Ammoniacal Silver nitrate solution and heated it produces a silver mirror on the walls of the test tube.
What is X?

Acetaldehyde?

Guess based on it being "Colourless Organic liquid, with a pungent fruity smell".

The reactions didn't help, but I googled (after guessing) and they do seem to fit.

yep very good, impressed with the guess based on just the physical appearance and the smell.

With the reactions - 2,4 DNP shows it is a carbonyl compound.

The iodine and sodium hydroxide is the iodoform test.
and confirms the presence of a

CH3
I
C==O
I
R

the ammoniacal silver nitrate (tollens reagent) is the key identifier as it shows the compound can be oxidised and the only carbonyl compound giving both a positive iodoform test and positive tollens reagent test is ethanal/acetaldehyde

K now someone else post a question

Go ahead Bunbury

1) Inorganic compound
2) Exists in two isotopologues that make it very useful in the energy industry
3) Solid at room temperature and pressure
4) Reacts with water forming corrosive, toxic products
5) Thousands of tons of it are stored around the world in the open air in sealed steel containers

Is that enough to go on?

uranium hexaflouride?

Right, except for spelling (it's hexafluoride not hexaflouride).

X has molecular mass 94

X reacts with NaOH forming a Salt Na⁺X^-

However on reacting X with Sodium Carbonate and Sodium Hydrogencarbonate
there appears to be no reaction.

Originally Posted by organic god

X has molecular mass 94

X reacts with NaOH forming a Salt Na⁺X^-

However on reacting X with Sodium Carbonate and Sodium Hydrogencarbonate
there appears to be no reaction.

Hmmm ... anything related to a list of reactivity?

So disgraceful that I study Chemistry, but I have simply no idea in it.

I'm confused. X must be an acid, so its anion shouldn't still be called X should it, since it's lost its H?

I can't come up with an acid with a molecular mass of 94.

Clue?

the negative sign is there in superscript maybe it is too difficult to see.

clue...it is an organic acid

Carbolic acid? C<sub>6</Sub>H<sub>5</Sub>OH

yep, also known as phenol

Originally Posted by organic god

the negative sign is there in superscript maybe it is too difficult to see.

No, I saw it there, and I see what you mean. The only difference between the acid and the anion is the loss of a proton, so X with superscript is the right way to show it.

Good one. Well done Kalster.

Originally Posted by KALSTER

Carbolic acid? C<sub>6</Sub>H<sub>5</Sub>OH

Originally Posted by organic god

yep, also known as phenol

a bit off track here but is phenol more acid or alcohol like? i got the impression in sch that its alcohol like thus would like to know how chemists used to name it carbolic acid. that said, why wouldn't it react with the other two chemicals?

It is only slightly acidic, therefore it doesn't react with the other two chemicals, but NaOH is a strong alkali so it does react with it.
The reason it can behave like an acid, is that the negative charge on the oxygen can be delocalised around the benzene ring allowing for it to be stable.

Truthfully, the name just popped into my head, I searched the chemical formula and counted up the molecular masses to verify. Kalster just lucky I guess.

So I should do a new one? It will be easy by default, so here goes:

It is a salt.
It is often encountered as heptahydrate.
The anhydrous form is used as a drying agent.
It is used in agriculture as a soil additive for crops like potatoes, roses, tomatoes, and peppers.
It’s an old diarrhoea remedy for adult chickens.
It can be used as laxative in humans.

I hope I gave enough clues. I have to admit also that I queried Wikipedia.

Originally Posted by KALSTER

Truthfully, the name just popped into my head, I searched the chemical formula and counted up the molecular masses to verify. Kalster just lucky I guess.

So I should do a new one? It will be easy by default, so here goes:

It is a salt.
It is often encountered as heptahydrate.
The anhydrous form is used as a drying agent.
It is used in agriculture as a soil additive for crops like potatoes, roses, tomatoes, and peppers.
It’s an old diarrhoea remedy for adult chickens.
It can be used as laxative in humans.

I hope I gave enough clues. I have to admit also that I queried Wikipedia.

Guess ... magnesium sulfate?

Got it! Now let the big boys play.

Errr ... I'm actually useless in Chemistry.

How about this?

Archibald visits a café. He orders something to be drunk, but it doesn't taste as usual. So, he decides to take a sample of it to be analyzed with an infra-red spectrometer. He doesn't find a peak between 2 500 /cm and 3 650 /cm. Thus, he goes back to the café and swears to the owner.

What compound do we usually find?

ok i'm a bit confused on the question here.

So the compound will usually give peaks at 2500 and 3650?

But on his IR he doesn't find them?

Originally Posted by organic god

ok i'm a bit confused on the question here.

So the compound will usually give peaks at 2500 and 3650?

But on his IR he doesn't find them?

Aye ... that is correct.

Hmm well it is in a cafe. so that probably means a drink of some sort.

The peak at 3650 probably corresponds to an alcohol,

2500 i'm not sure about yet.

I think the missing values probably correspond to the abscence of alcohol in the alcoholic drink.

something like a irish coffee but not totally sure

Originally Posted by organic god

Hmm well it is in a cafe. so that probably means a drink of some sort.

The peak at 3650 probably corresponds to an alcohol,

2500 i'm not sure about yet.

I think the missing values probably correspond to the abscence of alcohol in the alcoholic drink.

something like a irish coffee but not totally sure

No ...no ... no ... I think you misinterpreted it and I misinterpreted your question.

I said between 2 500 and 3 650.

And I asked what compound we usually found.

Oh, I give another clue because like what I said, I'm useless in Chemistry.

It's Captain Archibald Haddock.

So there is usually a peak between 2500 and 3600?

but this time there isn't

and the compound we want to find is the one that does give a peak between 2500 and 3600.?

Originally Posted by organic god

So there is usually a peak between 2500 and 3600?

but this time there isn't

and the compound we want to find is the one that does give a peak between 2500 and 3600.?

Right.

well the best i can guess is that the compound is some kind of alcohol, but the captain is angry because the alcoholic part (2500-3650) is missing.
so compound is like vodka or brandy or something

Originally Posted by organic god

well the best i can guess is that the compound is some kind of alcohol, but the captain is angry because the alcoholic part (2500-3650) is missing.
so compound is like vodka or brandy or something

Aye ... the question is the alcoholic part.

Darn, I was going to guess caffeine.

sorry george got no idea

I just wanted to post a new clue.

• It has a peak between 2 500 /cm and 3 650 /cm in its infrared spectrum.
• It gives three signals in its nuclear-magnetic-resonance spectrum.
• Two signals are a triplet each. The ratio of the integration traces is 1 : 3.
• One signal is a multiplet.

I don't know, Haddock likes whisky though.

:-D

Originally Posted by thyristor

I don't know, Haddock likes whisky though.

:-D

Aye ... the compound is contained in every whisky.

Something to do with malt?

Originally Posted by thyristor

Something to do with malt?

With the process, yes.

Btw, are you French? If so, do you know the etymology for the word limousine (I'm thinking of the car)? I've been thinking about this question fpr a long time

Now to your question: I'm sorry, I don't know the answer.

Originally Posted by thyristor

Btw, are you French? If so, do you know the etymology for the word limousine (I'm thinking of the car)? I've been thinking about this question fpr a long time

Now to your question: I'm sorry, I don't know the answer.

Nope. I'm not French.

It's derived from the city of Limoges.

I think Haddock was addicted to absinthe and the missing ingredient was thujone.

Originally Posted by Bunbury

It's derived from the city of Limoges.

I think Haddock was addicted to absinthe and the missing ingredient was thujone.

Thujone gives more than three signals in a NMR spectrum.

Another clue:
It's produced with help of Saccharomyces cerevisiae.

Ethanol then? I thought we'd eliminated that.

i don't think ethanol fits the NMR spectrum, as it would have a singlet for the -OH proton

Originally Posted by organic god

i don't think ethanol fits the NMR spectrum, as it would have a singlet for the -OH proton

Code:

    H   H
    |   |
H---C---C---O---H
    |   |
    H   H

triplet - multiplet - triplet

Next, Bunbury.

...no the OH peak is a singlet.

new rule to the game, clues have to be correct

Originally Posted by organic god

...no the OH peak is a singlet.

new rule to the game, clues have to be correct

May I ask why you're so sure? Why is the OH peak a singlet?

The Oxygen prevents the Proton on the OH group, being effected by the protons on the CH2 group therefore they do not effect it's spin.

Originally Posted by organic god

The Oxygen prevents the Proton on the OH group, being effected by the protons on the CH2 group therefore they do not effect it's spin.

They do. Otherwise, the CH2 group must be a quartet. The CH3 group is a triplet because of the CH2 group and the OH group is a triplet because of the same reason. The result is that the CH2 group will show eight peaks.

have you even looked at an NMR spectrum for ethanol

have you ever studied NMR?

Originally Posted by organic god

have you even looked at an NMR spectrum for ethanol

have you ever studied NMR?

That is why I asked you why you were so sure.

I've had an internship where I worked with IR, NMR and MS in one time.

Well i have studied NMR. and unless we have pure ethanol then it is only going to give a singlet due to the exchange between water protons and the OH proton. as the ethanol is in a beverage i doubt the NMR is pure

Originally Posted by organic god

Well i have studied NMR. and unless we have pure ethanol then it is only going to give a singlet due to the exchange between water protons and the OH proton. as the ethanol is in a beverage i doubt the NMR is pure

I didn't say that the captain analyzed the whisky with a NMR. I did say that he used an IR spectrometer. Just because people seemed to be stuck, I added some clues with a direct relation to the compound.

Oh, and I suppose that you studied it in the basic view of organic chemistry.

There is not much more to say except that unless the ethanol is pure it will give a singlet. nothing else is relevant

Originally Posted by organic god

There is not much more to say except that unless the ethanol is pure it will give a singlet. nothing else is relevant

Yeah, that is what you've done in organic chemistry.

i've done more than that, but the question didn't need an extensive knowledge of organic chemistry and the clues were poorly worded tbh

Originally Posted by organic god

i've done more than that, but the question didn't need an extensive knowledge of organic chemistry and the clues were poorly worded tbh

If you look at some great analytical-chemistry books, you'll get more information than what you currently have.

And whenever I write something, it's based on facts or at least, on sources. Do you think my work is creating internet phenomena?

And after reading the pages, I want you to take a look at what I posted above. It's simply logical.

Rocket science? Ignorance?

I think we should put this one down to a miscommunication, and organic god should pose the next question. My assumption of ethanol doesn't qualify - I have no knowledge of spectroscopy.

Go for it OG.