[Working_Mud7894]

Trying to generate pure Ammonium Nitrate for a school project. I want to use the crystals in an endothermic reaction/


1. Dissolved the ammonium nitrate fertilizer in water
2. Filtered out impurities
3. Boiled n stove to remove excess water
4. Let it cool

I get a white solid disc. Did not crystalize. Not sure I can use this for an endothermic reaction. What am I doing wrong?

Thank you

[marquis]

If you have a thermometer, try putting the thermometer in water and then adding the ammonium nitrate.  Record the initial temp and then see how it changes.  If your ammonium nitrate is good, the temp should go down.  Then you are good to go.  Try and keep the amount of water relatively small.

Many try and purify ammonium nitrate for other purposes.  Can't help you there.

[Borek]

Not the safest compound to work with.

What you got is probably a solid mixture of non-stoichiometric hydrates, some compounds can solidify this way instead of producing nice crystals. Check if slowing down the cooling process won't help, or if adding a crystal to the saturated solution (so called inoculation) won't start the crystallization.

And google for "growing crystals", there are some general guidelines that should help.

[Hunter2]

1. Dissolved the ammonium nitrate fertilizer in water

I think to use a fertilizer is anyway no good idea, because it's a mixture of different compounds. To produce nice crystals use the clean product.
As already mentioned ammonium nitrate is a dangerous  compound.
It can explode by itself.
Last one happened in Beirut.

https://www.google.com/url?sa=t&source=web&cd=&ved=2ahUKEwiM7Mbz3KCMAxUb7AIHHX1NEqwQwqsBegQIChAF&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DBJmOPnRAJoo&usg=AOvVaw00A_wYKKGB356FXxEEVDqD&opi=89978449

[Working_Mud7894]

Thank you all for the responses. I am aware of the dangers. I will make sure I won't heat the solid substance.

I heated the solution till it is concentrated and then left to cool. I have attached the picture. It is hard solid disk there. I will try again with slow cooling.