NaCl crystal growing prac?

[Rowyrow]

Does anyone know of a good crstal growing prac using SOdium Chloride? pparently we are no longer allowed to use COpper sulfate. I have been experimenting with table salt and rock salt (and food colouring to make it a bit more interesting but im not getting good results. Any trick to it?

[Judy R]

Sodium chloride is not the best crystal grower however if you drip very concentrated salt soln over a suspended pipe cleaner you will grow some long crystals.
potassium aluminium sulfate is cheap and grows great crystals

[Labbie]

Can i ask Why can you not use copper Sulfate any more??????????????????

[Rowyrow]

Oww fantastic! is it easy to get hold of? Being in the NT everything takes forever! can i get it from say a harware store of pool supply?

[rae]

Do a search for "crystallisation prac using Borax". I believe it is very good. Never done it myself but I think it came highly recommended.

Lorrae

[Jen1]

I'm with labbie - who says we cant use copper sulphate anymore?????????
Must be members of the fun police, they ruin all our fun!
I'm glad no one has told me we can't use it.

[Rowyrow]

Have just been told NO

[Labbie]

May we ask are you a DET school or private? Do you use the CSIS? I just can not believe this.

[Rowyrow]

Private school in the NT we are allowed to use copper sulfate just not to grow crystals, dont think it's a safety thing more of a cost thing maybe?

[RosalieM]

If it's a cost thing, just re-use the crystals. You can re-dissolve them and keep it ready for the following year in a container labelled "copper sulfate for crystal growing prac".

[Lyn]

Hi Rowyrow,
According to DEET who have put out a list for chemicals approved for use in Territory schools copper sulfate is not on the banned list. It is classified as an approved chemical for school use. They also have a list of banned chemicals. I think perhaps that you may not have this information at hand in your prep room. I have rung DET to find out the site that you can download this information and someone will get back to me with the details. If they can't find the information I will just have to figure out how to make an attachment of the info I have and try and send it to you. In the meantime you can download further information for lab. techs. Just google - DET NT OH&S manual science guidelines November 2008. This is the manual that was put together for lab techs in NT schools. Print it off and put it in a folder for your own reference.
Lyn.
P.S. We are using copper sulfate because the practicals in the student textbooks specify the use of copper sulfate. Perhaps your science person has gone overboard with their risk assessment. I ordered in 5kg of the stuff last year because they use it often for the junior classes and it was cheaper in bulk -Technical grade for $76. I got better quality copper sulfate (more expensive) for the Y11 & Y12 classes. I do a lot of recycling but at a certain point enough is enough.

[Rowyrow]

Thanks Lyn,
Yeah I have the Science Guidelines thing. It was the teacher that said they arn't allowed to use it and to be honest I was a bit stumped to. I will have to ask her what she means. Thanks everyone for your help.

[bindi]

Rowyrow,
I have been recycling Copper Sulphate for the last 6 years and have never had to buy any....thus its very affordable.
Any experiment that is done with CuSO4 is recollected and just reused.
I collect the crystals (solids to make solution) & solutions to make the crystals.
Most of the junior classes dont need it to to be pure.
I keep the purchased stock which gets used in small quanities in Senior Chem only.

[smiley]

Row,

Get the cheap stuff in a bucket from Bunnings, then recycle it.

BTW what's the weather like there at the moment. We couldn't grow crystals at the moment if you paid us to. Even spilled salt on the table turns into little drops of salt water overnight. Might have to use an incubator or whatever to make the crystals.

[Rowyrow]

Drying out a bit actually. Hasn't been as wet as the weather man keeps forcasting according to him it rains EVERYDAY in the afternoon. This week not so much, so the humidity isn't too bad. Still HOT as tho!

[sunray18]

ALTERNATIVE CRYSTAL FORMING EXPERIMENTS
Sucrose Crystals
1 Make a saturated solution of sucrose – keep it hot in a water bath.
2 Smear a small amount on glass slides and place under a microscope.
3 Students can view the crystals as they are forming.
This works very well with many different salts.

Urea Crystals
1 Use fertilizer that has a high content of urea.
2 Mix it in hot water and add colour to it with food dye.
3 Cut out a cardboard ‘tree’.
4 Using sticky tape, secure the tree into a plastic tray.
5 Add the Urea solution to the tray.

Salt ‘Crowns’ –plus
{crystal formation plus chromatography}

1 Cut filter paper into a crown shape and form a cylinder weith it.
2 Make a saturated salt solution and add food colouring.
3 Pour the solution into a Petri dish and stand the ‘crown’ into it.
4 Crystals should grow on the crown after a few days, and ,depending on the colour used, the filter paper shows a great example of chromatography.

Borax Snowflake
Use 3 tablespoons borax per cup of water. Dissolve in boiling water.
It is okay if some undissolved borax settles to the bottom of the jar.

If desired, you may tint the mixture with food color.

Make a snowflake shape with pipe cleaners

Hang the pipe cleaner snowflake into the jar so that the snowflake is completely immersed in solution.

When it has completely crystalised, hang up in your room... it is said to deter flies.. but is that a myth??

Some extra ideas perhaps...

[JelJane]

I found this website quite useful... http://www.waynesthisandthat.com/crystals.htm#best