Sciencemadness Discussion Board

Growing copper Nitrate crystals

Little_Ghost_again - 25-12-2014 at 16:15

Hi
would it be possible to make then grow copper nitrate crystals? I know its a mare with absorbing water from the air but could it be done in a desiccator with say sodium hydroxide or calcium oxide as the desiccant? maybe under a small reduced pressure?
I am collecting a small display of copper and iron compounds (dont ask me why as I have no idea).
I would like the sulphate and nitrate forms as crystals sealed in inert dry gas afterwards.

Metacelsus - 25-12-2014 at 17:21

I don't see why not. If you have a saturated solution and slowly evaporate it, you'll probably get some nice crystals.

Little_Ghost_again - 25-12-2014 at 22:14

Ok thanks I might give it a go, I tried making some ages ago and it went like slush in minuets, so this time a might try a desiccator. There are some other nice copper compounds but seems alot of the ones I like go bang!

Oscilllator - 25-12-2014 at 23:12

Sure they can be grown. I have made them (accidentally) in the past by dissolving copper in concentrated nitric acid. When the highly exothermic reaction had cooled, some crystals crystallised out. I imagine the difficulty lies in evaporating the solution entirely.

Little_Ghost_again - 26-12-2014 at 06:03

Quote: Originally posted by Oscilllator  
Sure they can be grown. I have made them (accidentally) in the past by dissolving copper in concentrated nitric acid. When the highly exothermic reaction had cooled, some crystals crystallised out. I imagine the difficulty lies in evaporating the solution entirely.


I have a sheet of acrylic and marine ply staring at me in the shed, so maybe time to get some long arm nitrile gloves and make a glove box :D. Or just use a large desiccator with some calcium oxide and sodium hydroxide as a desiccator.

blogfast25 - 26-12-2014 at 06:44

Quote: Originally posted by Little_Ghost_again  

I have a sheet of acrylic and marine ply staring at me in the shed, so maybe time to get some long arm nitrile gloves and make a glove box :D. Or just use a large desiccator with some calcium oxide and sodium hydroxide as a desiccator.


There's no need for a glove box here. Copper(II) nitrate has a steep solubility/temperature dependence, so thermal recrystallization is perfectly possible.

Slow evaporation of the water in the supernatant in a warm place should also work.

The real problem is keeping them. As you wrote, they're very hygroscopic and tend to reduce to mush quickly.

Little_Ghost_again - 26-12-2014 at 17:04

Quote: Originally posted by blogfast25  
Quote: Originally posted by Little_Ghost_again  

I have a sheet of acrylic and marine ply staring at me in the shed, so maybe time to get some long arm nitrile gloves and make a glove box :D. Or just use a large desiccator with some calcium oxide and sodium hydroxide as a desiccator.


There's no need for a glove box here. Copper(II) nitrate has a steep solubility/temperature dependence, so thermal recrystallization is perfectly possible.

Slow evaporation of the water in the supernatant in a warm place should also work.

The real problem is keeping them. As you wrote, they're very hygroscopic and tend to reduce to mush quickly.


By growing them I am actually after growing them large, not just getting them to form. I will give the desiccator a go.