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| Нуждаюсь в совете http://www.chemistry-chemists.com/forum/viewtopic.php?f=9&t=123 |
Page 306 of 318 |
| Author: | SKLYANKA [ 12 May 2022 21:24 ] |
| Post subject: | Re: Нуждаюсь в совете |
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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| Author: | antabu [ 13 May 2022 06:39 ] |
| Post subject: | Re: Нуждаюсь в совете |
Если взять димексид, может быть впитается... |
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| Author: | Volodymyr5 [ 13 May 2022 10:33 ] |
| Post subject: | Re: Нуждаюсь в совете |
Раз вы не побоялись пробовать белизну - попробуйте подкисленный сульфит натрия или метабисульфит. Сернистый ангидрид образует с |
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| Author: | vano34 [ 17 May 2022 12:08 ] | ||
| Post subject: | Re: Нуждаюсь в совете | ||
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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| Author: | Hayamye [ 17 May 2022 15:06 ] |
| Post subject: | помогите понять реакции со свинцом |
Будет ли реакция Свинца с гидрохиноном? Реакция Поливининилового спирта и свинца? |
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| Author: | Volodymyr [ 17 May 2022 15:39 ] |
| Post subject: | Re: Нуждаюсь в совете |
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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| Author: | vano34 [ 23 May 2022 23:52 ] |
| Post subject: | Re: Нуждаюсь в совете |
How to separate carbon and manganese dioxide after electrolysis and determine their ratio by analysis? |
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| Author: | Volodymyr [ 24 May 2022 09:36 ] |
| Post subject: | Re: Нуждаюсь в совете |
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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| Author: | vano34 [ 24 May 2022 18:11 ] |
| Post subject: | Re: Нуждаюсь в совете |
thank you Volodymyr so much! |
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| Author: | vano34 [ 25 May 2022 22:28 ] |
| Post subject: | Re: Нуждаюсь в совете |
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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| Author: | Volodymyr [ 26 May 2022 10:09 ] |
| Post subject: | Re: Нуждаюсь в совете |
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 Attachment: 376.jpg [ 534.34 KiB | Viewed 2908 times ] Attachment:
File comment: Kirk-Othmer encyclopedia of chemical technology, Vol.5,
Vol_5 Carbon and Graphite Fibers to Chlorohydrocarbons.djvu [7.47 MiB]
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| Author: | vano34 [ 26 May 2022 10:45 ] |
| Post subject: | Re: Нуждаюсь в совете |
Thank you Volodymyr! |
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| Author: | vano34 [ 26 May 2022 10:48 ] | ||||
| Post subject: | Re: Нуждаюсь в совете | ||||
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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| Author: | Volodymyr [ 26 May 2022 15:57 ] |
| Post subject: | Re: Нуждаюсь в совете |
Quote: 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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| Author: | vano34 [ 26 May 2022 17:26 ] |
| Post subject: | Re: Нуждаюсь в совете |
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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| Author: | Volodymyr [ 26 May 2022 17:55 ] |
| Post subject: | Re: Нуждаюсь в совете |
Hard to say. Titanium metal is resistant to nitric acid. Nickel is very common in vacuum tubes. ________ Titanium is not used in heating spirals. Titanium is used in getters Quote: A getter is a deposit of reactive material that is placed inside a vacuum system to complete and maintain the vacuum. Attachment: Getter_diagram.png [ 413.39 KiB | Viewed 2875 times ] |
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| Author: | vano34 [ 27 May 2022 10:07 ] | |||
| Post subject: | Re: Нуждаюсь в совете | |||
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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| Author: | Volodymyr [ 27 May 2022 18:25 ] |
| Post subject: | Re: Нуждаюсь в совете |
I think it's getters. Typically titanium, tantalum or barium is used. |
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| Author: | Ing.P. [ 27 May 2022 19:25 ] |
| Post subject: | Re: Нуждаюсь в совете |
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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| Author: | vano34 [ 27 May 2022 20:01 ] |
| Post subject: | Re: Нуждаюсь в совете |
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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