Chemistry Forum

Hey there! New here
I am trying to make copper nitrate so I can patinate copper sheet.I have previously used this in a formula of 80 grams per litre of water The recipe I have-
350g copper sulphate 1L H₂O @ 20 c
1290g calcium nitrate 1 l H₂O @ 20 c
It can also be prepared by mixing two concentrated solutions of calcium nitrate and copper(II) sulfate. Calcium sulfate will precipitate, while the much more soluble copper nitrate will remain in solution. Filter the solution (it's recommended you use vacuum filtration as gypsum tends to hold water.
Will this work? I don't need to make the crystals just get a liquid at the above mentioned ratio of 80 grams per litre ( it does not have to be excact )
Thanks in advance Chris

Yes it will work. But I am wondering about the masses.

For the reaction

CuSO₄ + Ca(NO₃)₂ => Cu(NO₃)₂ + CaSO₄

1 mol of each is necessary.

Which salt do you used. The hydrat one or the dry one.

350 g Pentahydrat gives 88,9 g/ l Cu The dry salt would give 138 g/l Cu

So what does the 80 g / l means.

CuSO₄ to CuSO₄ x 5 H₂O and Ca(NO₃)₂ to Ca(NO₃)₂ × 4 H₂O

For the weight it make a difference.

Hey there Thanks for the reply
Sorry Chemistry is not my area!

I got the weights of the two chemicals by finding the saturated solutions of them at 20 degrees celcius as the recipe stated to use saturated solutions at that temperature
Is this wrong?
Should I use equal measures?
The copper salt is
Copper sulphate pentahydrate
Copper (2) sulfate
Calcium nitrate - CA (NO₃)₂

The 80 grams per litre
was the amount of copper nitrate crystals I used to add to water when I had bought them ready to go. This solution was then added to wood shavings and placed over copper sheet to give a blue / green marble like look to the copper

A saturated solution of CuSO₄ x 5 H₂O contain 317 g/l and not 80 g/ l
So 350 g comes close to it, but it is too much.
For Ca(NO₃)₂ its 1470g/ l. So 1290 g/ l is also close to it.

For 317g (1,2 mol) Copper sulfate 5 hydrate about 200 g of Calciumnitrate is necessary. This will obtain 225 g/ l of coppernitrate. For 80 g/l only 112g copper sulfate and 72 g calcium nitrate is necessary.

Thanks
"For 317g (1,2 mol) Copper sulfate 5 hydrate about 200 g of Calciumnitrate is necessary."
So the above recipe both chemicals dissolved in 1 litre of water or less water for the calcium nitrate so it is iust saturated ?

Coppersulfate 317 g/l is saturated solution. Calciumnitrate 200 g is the calculated amount to react. Saturated solution with 1290 g not necessary. To much will be wasted.

Thanks very much
I will give it a go