Sciencemadness Discussion Board - synthesis of Calcium Nitrate

synthesis of Calcium Nitrate

toothpick93 - 26-2-2013 at 23:54

Sodium and Potassium nitrate can both be made with ammonium nitrate. I like nitrate's alot and always wondered how i can get calcium nitrate using ammonium nitrate to start off. Normally you need 2 soluble solutions and you get 1 solid and one solution, or 2 solutions and one can be boiled off leaving a solid. Could this be the case but with calcium compound?

There isnt much soluble calcium compounds that would work with ammonium nitrate. does anyone know ammonium hypochlorites properties? ive googled it but not much came up on that chemical, as well as no msds for it. Does anyone have any idea on how i could make calcium nitrate with OTC products?

""Nitric acid is way out of my way to make so i cant use it""

DraconicAcid - 27-2-2013 at 00:04

Calcium hydroxide and ammonium nitrate should give you calcium nitrate, ammonia and water.

toothpick93 - 27-2-2013 at 00:47

Would i have to boil it or would it react very slowly on its own?

KonkreteRocketry - 27-2-2013 at 07:19

Quote: Originally posted by DraconicAcid

Calcium hydroxide and ammonium nitrate should give you calcium nitrate, ammonia and water.

Wow ammonia, interesting...

DraconicAcid - 27-2-2013 at 09:12

Quote: Originally posted by toothpick93

Would i have to boil it or would it react very slowly on its own?

It will react fairly quickly. Add the ammonium nitrate slowly to avoid too vigorous a reaction, just in case.

AndersHoveland - 27-2-2013 at 11:51

It normally would not be referred to as a "synthesis", because all we are really doing is separating calcium and nitrate ions, and isolating them together in the new compound. No new covalent bonds are being formed. It would be more appropriate to refer to it as "preparation" or calcium nitrate. The word 'sythesis' is much more commonly used in organic chemistry.

Calcium nitrate is deliquescent, so you would have to boil out all the water, and then carefully bake the remaining powder to remove all the moisture.

It is true that it can be made using NH4NO3, but I find that to be an unnecessary waste. Usually one would only go the ammonium route when they are making perchlorate salts, since ammonium perchlorate is so easy to isolate in the first place because of its unusually low solubility.

[Edited on 27-2-2013 by AndersHoveland]

DraconicAcid - 27-2-2013 at 12:13

Quote: Originally posted by AndersHoveland

Calcium nitrate is deliquescent, so you would have to boil out all the water, and then carefully bake the remaining powder to remove all the moisture.

I'm not sure boiling out the water will work- calcium tetrahydrate is very stable and melts at 45oC. The Merck index does not say at what temperature it dehydrates (or if it does so without decomposition). The CRC says it decomposes at 123oC, but doesn't specify if it gives anhydrous calcium nitrate at that temp or not.

Formatik - 27-2-2013 at 20:26

I've attempted synthesis of calcium perchlorate through ammonium perchlorate and calcium hydroxide (suspended in solution).

There was partial reaction from these two, but even boiling the mixture didn't cause the calcium hydroxide to go into solution, so the reaction was greatly limited by the insolubility of calcium hydroxide (here).

I'm betting it's the same for ammonium nitrate and calcium hydroxide in solution.

Calcium nitrate can be dehydrated, the tetrahydrate boils at 132 C, and this salt is said to become anhydrous after 1/3 of the water has been driven off (JACS 5, 164). That JACS article is a great reference on the nitrates decomposing. Download it. Do it. Do it now.

DraconicAcid - 27-2-2013 at 20:40

Quote: Originally posted by Formatik

I've attempted synthesis of calcium perchlorate through ammonium perchlorate and calcium hydroxide (suspended in solution).

There was partial reaction from these two, but even boiling the mixture didn't cause the calcium hydroxide to go into solution, so the reaction was greatly limited by the insolubility of calcium hydroxide (here).

I'm betting it's the same for ammonium nitrate and calcium hydroxide in solution.

That's weird- calcium hydroxide is slightly soluble ( more so than other non-alkali hydroxides), and I'd have expected it to react. Saturated calcium hydroxide has a pH of 12.4 (Merck), which should be plenty basic enough to drive off ammonia. (Merck also adds that it is soluble in ammonium chloride solution.)

Was the calcium hydroxide fresh? If it's old, it will absorb CO2 from the air to form the carbonate, which isn't going to react very well with the ammonium nitrate.

Quote:

Calcium nitrate can be dehydrated, the tetrahydrate boils at 132 C, and this salt is said to become anhydrous after 1/3 of the water has been driven off (JACS 5, 164). That JACS article is a great reference on the nitrates decomposing. Download it. Do it. Do it now.

Thanks for that.

elementcollector1 - 27-2-2013 at 20:52

Calcium hydroxide is actually *less* soluble in hot water than cold. Maybe chilling your solution?
The problem with calcium hydroxide is that even thought it dissolves in water, it's not that much.

DraconicAcid - 27-2-2013 at 20:54

Quote: Originally posted by elementcollector1

Calcium hydroxide is actually *less* soluble in hot water than cold. Maybe chilling your solution?
The problem with calcium hydroxide is that even thought it dissolves in water, it's not that much.

It's possible that once the reaction begins to go, the build-up of calcium ions in solution prevents the calcium hydroxide from dissolving further....

Formatik - 27-2-2013 at 23:53

The ammonium nitrate method will certainly work. But it's a boiling down and scraping for yield-type reaction, which are never fun.

1.89g Ca(OH)2 in 1000mL of water to be more precise (if at 0 C). Which would give 4.18g of Ca(NO3)2 in theory.

To put things in perspective, if you want 100g Ca(NO3)2, you need 45.24g Ca(OH)2 in about 24,000 mL of H2O!

Note: Solubility data of Ca(OH)2: 4.447 g/L aq. NH4Cl solvates 4.42g/L Ca(OH)2 at 25 C (source). So if it is similar for NH4NO3, then you would need less water (2.33 times less water if it's the same, but it's still a ton of H2O).

[Edited on 28-2-2013 by Formatik]

IrC - 28-2-2013 at 00:56

Wouldn't nitric acid be an easier route?

Ca(OH)2 + 2HNO3 = Ca(NO3)2 + 2H2O

Or using Ammonia:

CaO + 2NH3 + 4O2 = Ca(NO3)2 + 3H2O

toothpick93 - 1-3-2013 at 00:09

Quote: Originally posted by IrC

Wouldn't nitric acid be an easier route?

Ca(OH)2 + 2HNO3 = Ca(NO3)2 + 2H2O

Or using Ammonia:

CaO + 2NH3 + 4O2 = Ca(NO3)2 + 3H2O

It would be a much easier route and wouldn't need to ask how to make it other wise but i dont have the equipment to make nitric acid at home unless i make crude nitric acid.

for the ammonia route, i dont have a the right apparatus to lead ammonia and oxygen into calcium oxide.

Would a solution of Lithium Hydroxide react with ammonium nitrate?

PS: Reason for using ammonium nitrate all the time is it is readily available to me from the chemist and most easiest to get then other nitrates

IrC - 1-3-2013 at 17:50

I would think it would yielding Lithium nitrate and Ammonium Hydroxide but I am not one of the Gurus in Chemistry who could answer with greater certainty. However this would certainly not give you the Calcium nitrate you were looking for. But you knew that.

Formatik - 1-3-2013 at 23:31

Quote: Originally posted by IrC

Wouldn't nitric acid be an easier route?

Ca(OH)2 + 2HNO3 = Ca(NO3)2 + 2H2O

Certainly, but some folk around here like to do things the hard way.

Quote:

Or using Ammonia:

CaO + 2NH3 + 4O2 = Ca(NO3)2 + 3H2O

That can work if the ammonia is oxidized first, in something like the Ostwald process. Then the formed nitrogen oxides are combined directly with Ca(OH)2 or CaO at moderate heat. It's quite painstaking.

Quote: Originally posted by toothpick93

Would a solution of Lithium Hydroxide react with ammonium nitrate?

Lithium hydroxide isn't the most soluble alkali hydroxide, but it should easily work, and better than calcium hydroxide. I don't know why anyone would want to exchange these nitrates for one another.

AJKOER - 2-3-2013 at 08:57

Quote: Originally posted by Formatik

The ammonium nitrate method will certainly work. But it's a boiling down and scraping for yield-type reaction, which are never fun.

1.89g Ca(OH)2 in 1000mL of water to be more precise (if at 0 C). Which would give 4.18g of Ca(NO3)2 in theory.

To put things in perspective, if you want 100g Ca(NO3)2, you need 45.24g Ca(OH)2 in about 24,000 mL of H2O!

Note: Solubility data of Ca(OH)2: 4.447 g/L aq. NH4Cl solvates 4.42g/L Ca(OH)2 at 25 C (source). So if it is similar for NH4NO3, then you would need less water (2.33 times less water if it's the same, but it's still a ton of H2O).

[Edited on 28-2-2013 by Formatik]

Yes, Formatik, you are absolutely right. In fact, commercial processes employing Ca(OH)2 add NH4Cl or NH4NO3 to greatly increase the solubility of Ca(OH)2. As to why this occurs, find my comments in another thread. Please refer to http://www.sciencemadness.org/talk/viewthread.php?tid=23482&... some may find my comments on increasing Ca(OH)2 solubility (especially in dilute acids) to be interesting, educational and even useful.

Bottom line, if you want to pretend that you know what you are doing continue as is, but if you really want to produce Ca(NO3)2 pay attention.

[Edited on 2-3-2013 by AJKOER]

toothpick93 - 4-3-2013 at 05:31

I want to explore the oxidation of chemicals that produce colour. Potassium Nitrate burns with purple, Sodium with yellow, Calcium with orange, Lithium with red. Because ammonium nitrate outdoes react the same way, i normally use that as a precursor to make other nitrates that have the property to burn with sugar to produce a colour.

Is calcium hydroxide the only chemical that would react with ammonium nitrate, or could there be more other calcium compounds?

MrHomeScientist - 4-3-2013 at 07:39

If you're just looking to do the flame tests, nitrates aren't necessary. I think chlorides are most commonly used.

If you're trying out the "rocket candy" mixture of sugar and a nitrate salt, potassium nitrate is most commonly used, to burn with a lilac color (as you said). I've had limited success with mixing other chemicals into this mix to color it - i.e. a bit of boric acid gives it a green tint. Too much of the additive, though, and it has a very hard time igniting. Too little, and the color isn't visible. Tough to get working right, but if you can't make the nitrate salts you want it might be worth a try.

toothpick93 - 4-3-2013 at 08:00

Chlorides are too easy tho, i like the science behind the making of other chemicals