[hydrowire]

allo people,

I 'took' about 0.4 Litres of Copper Sulphate solution from skul today, its labeled 1 mol/L. My purpose is I try to make some really nice copper sulphate crystal with this soulution. I tried to look for pentahydrate one but only found an empty bottle so i have no choice.

I heat it and salt were present. As I know, to grow crystal u need supersaturated salt solution right? So I plan to extract all salt from this solution to make my own supersaturated salt solution. Then I will grow some seed crystal n lastly hopefully grow a nice decent size crystal.

My question is, is it posibble to make crystal from this 1M salt solution? Anyone have a better way?

[Alberto_Kravina]

Put a piece of rope in the solution and wait a few days. After this few days the crystals grow on the rope, and after that just scrape the crystals off the piece of rope.  

[ATMyller]

The key to big crystals with regural lattice is slow solvent evaporation. one way to do it is to put saturated solution in a beaker and clockglass over it with some wires stuck inbetween. You'll need some saturated or atleast higher consentration solution for that. With 0.4 litres of 1M it'll takes weeks, maybe months and the crystals' total weight will be measures in milligrams.

[AgG]

concentrate the solution.  boil off the water to a suitable level and you should have crystals in no time.

[hydrowire]

thx for replying,

ATMyller, wats the clockglass you mean?

i pour some into a metal plate n boiled it, when all the water removed, i can only see bluish powder, no crystal. Will I spoil it if over heating the salt? Bcuz i planed to boil all back to dry substance n prepare again myself a very concentrated salt solution, is this a good way?

To make really nice crystal, more or less concentrate is better? if i doesn't care how long it takes.


Ok I boiled the solution now that it left 0.1 L, it should be approx. 4 M salt solution right? Is this enough to make crystal?

[ATMyller]

Clockglass (deutsch sprache verdammt) also known as watch class:
http://en.wikipedia.org/wiki/Watch_glass

4M solution might still be too dilute or it'll take a long time. It's better to use the solid salt to make some saturated solution. Heating won't affect the salt. Copper sulfate might release it's crystal water and turn white, but once you make it into solution it'll turn back blue.

[hydrowire]

Since now i figured that my 4M CuSO4 is insufficient to grow crystal, now i plan to make a supersaturated solution with NaCl which is table salt, then i will mix it with the CuSO4 to make it looks atleast pale blue. Is this possible by growing crystal out of a mixed salt solution? Will my NaCl salt crystal will really turn up blue if I mix with CuSO4?

[ATMyller]

More likely some NaCl and Na₂SO₄ will crystallize and Cu(II) remains in solution. The result would be something like this KNO₃ CuSO₄ mixture:
http://cwx.prenhall.com/petrucci/medialib/media_portfolio/text_images/FG14_09.JPG

Good quality crystals don't usually mix because diffrences in crystal lattice dimensions. Even if you vapourize all the solvent  the result will more likely to be white NaCl crystal and few blue CuSO₄ crystals not light blue crystals.

[mike]

Here are some crystal of copper sulfate I grew over the weekend. I used about 40g per 100mL in water then poured into petri dish added some seed crystals and left for the weekend.

http://www.chemicalforums.com/index.php?board=7;action=display;threadid=5031;start=0#lastPost