April 23, 2025, 01:11:45 PM
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Chemical Engineering Forum / Re: NO2 reduction
« Last post by Gamel on April 19, 2025, 02:05:21 PM »
I can't change pressure or composition. I have only physical means.
I can play with the container where the gas is in. Modify its material.
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Chemical Engineering Forum / Re: NO2 reduction
« Last post by Hunter2 on April 19, 2025, 01:47:13 PM »
What is the purpose  to do so.
I think you can only decrease pressure or rise temperature.
Also removing oxygen will shift to NO.
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Chemical Engineering Forum / NO2 reduction
« Last post by Gamel on April 19, 2025, 12:40:57 PM »
Hello
This is quite basic but I'm not an expert in chemistry...
2NO +O2 -> 2NO2
I need to slow down this reaction as much as possible, but the concentration of NO and O2 is fixed, and so is temperature and pressure. I can't add other chemicals...
Is there anything else that can be done e.g. applying electric voltage, magnetic fields, use the force...?
Thanks!
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Inorganic Chemistry Forum / Re: Less toxic substitute for Hydrazine?
« Last post by TheodorCurtius on April 16, 2025, 06:04:34 PM »
You could try formazine...It is used in the combustion synthesis of various semiconductors IIRC. It can be synthesized from the reaction of hydrazine sulfate and hexamine and precipitates from aqueous solutions as an insoluble and relatively benign polymer.
https://en.wikipedia.org/wiki/Formazine
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Found this cool document describing the synthesis of sodium nitrate and sodium nitrite by simple electrolysis of ammonia with iron electrodes!

https://figshare.com/articles/journal_contribution/Amateur_synthesis_of_sodium_nitrate_and_sodium_nitrite_by_electrolytic_oxidation_of_ammonia_in_a_diaphragm_separated_cell/28806389?file=53701400

Thought it might be interesting to share...
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Good idea.  We have made other nitro-aromatics or -heteroaromatics and the carbon attached to the nitrogen is often broader than the others.
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The signals may be overlapping. You can change solvent to pull them apart or use INEPT if they have different multiplicity I think.
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High School Chemistry Forum / Re: Claisen condensation....
« Last post by Hunter2 on April 11, 2025, 01:35:12 AM »
Generally Claisen condensation

Ester enolates can be formed with alkoxides, and they are good nucleophiles
Esters can undergo addition-elimination reactions with nucleophiles, otherwise known as nucleophilic acyl substitution. In the Claisen condensation the nucleophile is the ROC(O)CH2 group which displaces (RO-).
Alkoxides can be adequate leaving groups in this case, since they’re significantly weaker bases than ester enolates.
The product of a Claisen condensation is a beta-keto ester, which is a significantly stronger acid (pKa = 11) than either alcohols (pKa = 16-17) or esters (pKa = 25).
The reaction requires at least one equivalent of base since the enolate of the beta-keto ester product is not a strong enough base to deprotonate the starting ester.
A “crossed” Claisen condensation involves the enolate of one ester reacting as a nucleophile with a different (ideally non-enolizable) ester to give a beta-keto ester.

Mixed Claisen condensations are possible if the excess ester does not have protons at C-α. If both esters have α-protons, predominantly statistical mixtures of products can be expected.

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