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 Post subject: Re: Нуждаюсь в совете
PostPosted: 12 May 2022 21:24 
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я пробовал спиртом, ацетоном, только размазываетсся. белизна тоже не помогла, карбонат натрия не помог. чтобы он изменил цвет, его нужно окислить или восстановить? перекись с нашатырным тоже не особо помогает(

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 Post subject: Re: Нуждаюсь в совете
PostPosted: 13 May 2022 06:39 
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Если взять димексид, может быть впитается...

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 Post subject: Re: Нуждаюсь в совете
PostPosted: 13 May 2022 10:33 
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Раз вы не побоялись пробовать белизну - попробуйте подкисленный сульфит натрия или метабисульфит. Сернистый ангидрид образует с сульфитом фуксином бесцветное соединение.

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 Post subject: Re: Нуждаюсь в совете
PostPosted: 17 May 2022 12:08 
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Hello. I tried to make mercury cyanide from potassium hexacyanoferrate (II) and acidic solution of mercury nitrate. Why it has this colour did i made mercury ferocyanide? and how can i make pure white salt?


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 Post subject: помогите понять реакции со свинцом
PostPosted: 17 May 2022 15:06 
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Будет ли реакция Свинца с гидрохиноном? Реакция Поливининилового спирта и свинца?


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 Post subject: Re: Нуждаюсь в совете
PostPosted: 17 May 2022 15:39 
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vano34 wrote:
Hello. I tried to make mercury cyanide from potassium hexacyanoferrate (II) and acidic solution of mercury nitrate. Why it has this colour did i made mercury ferocyanide? and how can i make pure white salt?

Perhaps there was an admixture of mercury (I) that gave metallic mercury (gray color)?

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 Post subject: Re: Нуждаюсь в совете
PostPosted: 23 May 2022 23:52 
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How to separate carbon and manganese dioxide after electrolysis and determine their ratio by analysis?


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 Post subject: Re: Нуждаюсь в совете
PostPosted: 24 May 2022 09:36 
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1. + dilute H2SO4 + H2O2 (in small portions), weak heating = MnSO4
2. Filtration, washing
3. Dry and weight carbon
4. Titration of Mn(II) by EDTA (xylenol orange, urotropine buffer pH=5.5)

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 Post subject: Re: Нуждаюсь в совете
PostPosted: 24 May 2022 18:11 
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thank you Volodymyr so much!


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 Post subject: Re: Нуждаюсь в совете
PostPosted: 25 May 2022 22:28 
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hello! how can I make cesium metal from its sulfate? I know CsCl and Li or Ca method, but now I cant make apparatus. also I don't like the azide method and I cant try the dichromate Zr method because I don't have a zirconium powder. is there another method?


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 Post subject: Re: Нуждаюсь в совете
PostPosted: 26 May 2022 10:09 
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Quote:
Thermal Decomposition.
Cesium azide [22750-57-8], CsN3, which is prepared by reacting aqueous solutions of cesium sulfate and barium azide, melts at 326°C and decomposes at 390°C to cesium metal (32):
2 CsN3 => 3 N2 + 2 Cs

Kirk-Othmer encyclopedia of chemical technology, Vol.5, P.376
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 Post subject: Re: Нуждаюсь в совете
PostPosted: 26 May 2022 10:45 
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Thank you Volodymyr!


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 Post subject: Re: Нуждаюсь в совете
PostPosted: 26 May 2022 10:48 
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I'm just interested what is this grey metal or alloy inside the tube? also, can I find hafnium, zirconium, and such metals in these tubes. I don't care about gold and such metals.


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 Post subject: Re: Нуждаюсь в совете
PostPosted: 26 May 2022 15:57 
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The lamp anodes are coated with porous titanium. The white powder of the cathode is barium oxide (if removed, it will quickly become a hydroxide...)

Individual elements can be made of tantalum. Molybdenum grids of powerful generator lamps are gilded (anti-dynatron coating).

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 Post subject: Re: Нуждаюсь в совете
PostPosted: 26 May 2022 17:26 
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thanks! interesting. Did I dissolve maybe anode? in nitric acid. I don't know exactly which is the anode. so I dissolved this metal piece in acid then I get nickel nitrate solution and white precipitate, probably nitric acid oxidize titanium to its dioxide. what do you think?


edited: precipitate was from dissolving spirals in acid, maybe it was Ni-Ti heating spiral?


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 Post subject: Re: Нуждаюсь в совете
PostPosted: 26 May 2022 17:55 
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Hard to say. Titanium metal is resistant to nitric acid. Nickel is very common in vacuum tubes.
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Titanium is not used in heating spirals. Titanium is used in getters
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A getter is a deposit of reactive material that is placed inside a vacuum system to complete and maintain the vacuum.

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 Post subject: Re: Нуждаюсь в совете
PostPosted: 27 May 2022 10:07 
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thanks for the help. on the photos are they also getters yes? when I dissolved spirals in nitric acid I got light white precipitate and green solution. I thought it was titanium and nitric acid oxidise it more easily because it was in alloy with nickel.


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 Post subject: Re: Нуждаюсь в совете
PostPosted: 27 May 2022 18:25 
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I think it's getters. Typically titanium, tantalum or barium is used.

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 Post subject: Re: Нуждаюсь в совете
PostPosted: 27 May 2022 19:25 
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vano34 wrote:
thanks for the help. on the photos are they also getters yes? when I dissolved spirals in nitric acid I got light white precipitate and green solution. I thought it was titanium and nitric acid oxidise it more easily because it was in alloy with nickel.
Most common material for electron tube electrodes (especially anodes) is molybdenum and its alloys, so light white precipitate You got is probably molybdenic acid. Try to dissolve this precipitate in water ammonia and test it by "molybdenic blue" reaction. Heating filament ("spiral") is made usually of tungsten which reacts likewise. Control grids are coated sometimes with gold to decrease secondary emission.


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 Post subject: Re: Нуждаюсь в совете
PostPosted: 27 May 2022 20:01 
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thanks friends! maybe it is a molybdic acid because of colour, it has white-bluish colour, it dissolved in ammonia solution and yes i will try to reduce it with atomic hydrogen.


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