Chemistry: Discussion, Questions & Potential Solutions

[Draco7164]

How did you guys draw the skeletal structure for the molecule in NMR question?

[Mischi]

What did you guys get for "Propose a method to determine how quickly a solution of hydrogen peroxide decomposes when stored at a particular temperature"?
Thanks

[Lear]

How did you guys draw the skeletal structure for the molecule in NMR question?

Laws 12 has uploaded a picture of it in an earlier reply

[Draco7164]

What did you guys get for "Propose a method to determine how quickly a solution of hydrogen peroxide decomposes when stored at a particular temperature"?
Thanks

I talked about determining the rate of o2 production for the experiment. We could utilise a separate chamber where the oxygen gas enters and in the chamber a moniter could be employed to determine the amount of oygen that enters the chamber each minute (assuming that all oxygen gas enters the chamber). Do you guys think this feasible enough to gain some marks? It looks like a question where the examiner might accept intriguing option.

[zenith101]

Was the polarity of the electrode( W or Y can’t remember) positive?

[Lear]

Was the polarity of the electrode( W or Y can’t remember) positive?

I think I recall getting negative. H+ ions were being reduced to form H2 gas at that electrode. Cathode is Negative in an electrolytic cell.

[Mischi]

I think I recall getting negative. H+ ions were being reduced to form H2 gas at that electrode. Cathode is Negative in an electrolytic cell.

Same here

[billy606]

Same here

double that

[matthewmwps]

What did you guys get for "Propose a method to determine how quickly a solution of hydrogen peroxide decomposes when stored at a particular temperature"?
Thanks

I wrote on how the Oxygen gas created could be extracted, while a timer is used to record the time until no oxygen is found to form.
I not sure if i needed to say this other part, but i also mentioned that one method of seeing when all oxygen is made would be to put extracted oxygen into a combustion reaction with excess fuel, as when no more fuel combusts, all of H2O2 has decomposed.

[Draco7164]

For the same question about the electrode being negative in the electrolytic section, what did you guys write for the equation in the alkane electrolyte? Did you guys get OH- ions as products?

[Lear]

I think you can just measure the beaker every minute or so haha. If a gas is released the beaker weight will decrease.

[matthewmwps]

By the way, it is possible for the compound on the C-NMR question to be butan-1-amine instead of 2 methyl propan-1-amine?
Cause like, i said the peak at around 60 was the R3C-NH2 and the other one was R-CH2-R.

[Draco7164]

By the way, it is possible for the compound on the C-NMR question to be butan-1-amine instead of 2 methyl propan-1-amine?
Cause like, i said the peak at around 60 was the R3C-NH2 and the other one was R-CH2-R.

I believe the C NMR showed 3 peaks which corresponded to 3 carbon environments. Butan-1-amine has four carbon environments whilst the latter option has 3 carbon environments and so I chose the latter option and thats what I did. If those were the two option you wrote for the two structural isomers in the previous part, then you should be correct.

[matthewmwps]

I think you can just measure the beaker every minute or so haha. If a gas is released the beaker weight will decrease.

True, but my argument is that method assumes O2(g) is the only gas released, which depending of the temperature tested could be incorrect. (some H2O2 could vaporise)

Probably just me overthinking it though.

[jyce]

Possible for someone to upload a copy of the exam, please?