Sciencemadness Discussion Board

yellow calcium hydroxide + ammonium nitrate

Fluorite - 18-12-2020 at 05:24

I wanted to make calcium nitrate and ammonia gas but the mixture turned yellow what should I do? I need the ammonia too so I don't want to boil everything and also I tried before some reactions with calcium hydroxide like bubble chlorine to make calcium hypochlorite but I saw purple color? This could be manganese

if i bubble H2S can i remove heavy metals?

[Edited on 18-12-2020 by Fluorite]

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RustyShackleford - 18-12-2020 at 06:10

If you reflux the solution and lead the ammonia from the top of the condenser into distilled water with a tube you could separate the ammonia like you want. To remove the yellow stuff you can probably recrystallize it. The fertilizer grade calcium nitrate i buy comes in yellow pellets, which i dissolve, filter through paper and then boil down and let cool to crystallize.

[Edited on 18-12-2020 by RustyShackleford]

[Edited on 18-12-2020 by RustyShackleford]

Fluorite - 18-12-2020 at 06:19

Quote: Originally posted by RustyShackleford  
If you reflux the solution and lead the ammonia from the top of the condenser into distilled water with a tube you could separate the ammonia like you want. To remove the yellow stuff you can probably recrystallize it. The fertilizer grade calcium nitrate i buy comes in yellow pellets, which i dissolve, filter through paper and then boil down and let cool to crystallize.

[Edited on 18-12-2020 by RustyShackleford]

[Edited on 18-12-2020 by RustyShackleford]


interesting ! when i add CaOH to water the solution stays colourless i dont know why the reaction turned it yellow but maybe the same thing when i bubbled chlorine through CaOH to make hypochlorite i saw purple color permanganate obviously
you know what can break the ammonia metal complex?

[Edited on 18-12-2020 by Fluorite]

RustyShackleford - 18-12-2020 at 06:39

>you know what can break the ammonia metal complex?

acidifying would do that, but ofc that would work by reacting with the ammonia. I think your best bet for removing the yellow contamination is to just recrystallize the calcium nitrate after separating the ammonia by refluxing. H2S would react with the calcium so thats no good.

I dont really understand what you meant by purple permanganate color, but i find it highly unlikely the yellow color is caused by hypochlorite.

Maurice VD 37 - 18-12-2020 at 12:58

The yellow color is probably some iron impurity present in the chalk. CaO and Ca(OH)2 are usually made by heating marble or any other calcareous matter at very high temperature (1000°C). And this calcium carbonate is coming from a mine without further purification. It often contains a very small amount of iron(II) which is nearly colorless. But when heated in the air, it gets oxidized into Iron(III) which is deeply colored in yellow - brown. Usually this impurity does not intervene in the use of the calcium derivates obtained from this natural calcium carbonate. Nobody cares about the color.