Making crystals from different solutions

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shellythenewlabby
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School: Woonona High School
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Making crystals from different solutions

Post by shellythenewlabby » 07 Aug 2019, 09:59

Hi everyone...Im in need of help/suggestions...For science week next week the teachers want to make crystal gardens and have asked me to make larger sized crystals for them to place in a sodium silicate solution. I have made up solutions of iron chloride, manganese sulfate, copper chloride and iron sulfate by dissolving the solid into hot water to make a saturated solution...Do I leave them out to dry naturally or place them in oven and dry them out slowly?? :oops: :oops: :unsure: :unsure:

mtg
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Re: Making crystals from different solutions

Post by mtg » 07 Aug 2019, 13:12

I am trying to post some photos of ours. But the problem I always have is to get the solution to the right %. I try about 50% of the premade stuff but stronger works ok depending on your crystal. I use straight metallic compounds, I dont bother making big crystals, I have CuSO4 ones already and they worked OK as did the powder. We use Iron Chloride (orange and rapid growth), nickel sulphate (green), chromium potassium sulphate (black), manganese chloride (pink),cobalt chloride (dark red/pink), Copper Sulphate (blue) and I think the white is Aluminium Potassium Sulphate. I do them in specimen containers with lids as they last longer if there's no exposure to air.

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shellythenewlabby
Posts: 28
Joined: 01 Jul 2016, 12:17
School: Woonona High School
State/Location: NSW

Re: Making crystals from different solutions

Post by shellythenewlabby » 07 Aug 2019, 13:27

Hi mtg...do u just place the liquid into the specimen jar for them to form a crystal or do you dry it our first then place into jar...Sorry for asking but I have only done the CuSO4 before and not the other solutions. Thanks

MariaQ
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Re: Making crystals from different solutions

Post by MariaQ » 07 Aug 2019, 14:19

Just a heads up cobalt chloride solid in teacher only according to RissAssess, and only the most dilute solutions are suitable for student use, therefore we no longer use it in crystal gardens. Suspected of causing cancer and infertility, not something I want for our students :w00t: , well maybe one or two should be stopped from reproducing!!

mtg
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Joined: 15 Aug 2011, 10:48
Job Title: Lab Tech
School: NDSC
Suburb: west gippsland
State/Location: VIC

Re: Making crystals from different solutions

Post by mtg » 07 Aug 2019, 14:31

I put the solution (sodium Silicate) into a container, then (being mindful of hazards) using forceps drop the other metallic crystals into the solution, put the lid on then try not to move them.
Interestingly the one I am extra cautious with in Chromium Potassium Sulphate, CuSO4 is also toxic and shouldn't be handled if possible.
We also made Lead Acetate/Zinc crystals (again use PPE), (Lead Acetate soln onto a zinc strip), and copper wire coils (careful it isn't coated) with AgNO3 solution. These must be done under supervision or as demos.
I have one in the booklet just sent out from chemtalk "Chemistree".

mtg
Posts: 334
Joined: 15 Aug 2011, 10:48
Job Title: Lab Tech
School: NDSC
Suburb: west gippsland
State/Location: VIC

Re: Making crystals from different solutions

Post by mtg » 07 Aug 2019, 14:40

I haven't tried this yet. This a direct copy from "SCIENCE DEMONSTRATIONS EXPERIMENTS ETC FOR OPEN DAYS & PRIMARY SCHOOL VISITS".
Chemistree: Empty Aluminium Can
Copper Sulphate/salt solution (1 tsp CuSO4 + 2 tsp Salt/ 1 cup water)
glass jars
METHOD
1. Cut the top and bottom off an empty aluminium soft drink can. Now cut around and around the can to create a thin continuous spiral.Do not straighten it out as you cut. Now carefully mold the spiral into a cone. (Xmas tree shape)
2. Place the cone of aluminium inside a clear glass container which is slightly bigger than the cone. Prepare sufficient copper sulphate/salt soln to completely cover the cone.
3.Leave the chemistree for 24 hours. Since the reaction occurs most rapidly on the freshly cut edges you should have a lovely red chemistree.

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