Crystal growing - not gardens :)
-
dolphinscales
- Posts: 370
- Joined: 30 Oct 2006, 10:00
- Job Title: Laboratory Technican
- School: Mandurah Senior College
- State/Location: WA
Crystal growing - not gardens :)
Need to grow some crystals - besides copper sulphate and pot ash what else does everyone use - these are for what we call senior science - (equivalent in essence to multi strand in QLD ). They are to measure growth - so the growth on a string like salt strings done as kiddies is a suggestion as they can measure the growth up thr string and the width of the growth. other suggestions?
hi dolphinscales,
maybe this can help
silver nitrate
EQIPMENT NEEDED:
• Beaker
• Stirring rod
• Balance
• Test tube clamp
• Copper wire (clean it up with sand paper)
• Silver nitrate ( used silver nitrate is OK)
• Distilled water
Obtain one approximately 30-cm piece of copper wire. Coil it around a pencil. It should be an open coil and leave about 5 cm of wire uncoiled to act as a handle.
Use the electronic balance to weigh the copper wire coil. Make sure that none of the wire is touching the balance base. Record this value in your data table.
Make sure the test tube clamp is attached to the ring stand, about 10 cm down from the top.
Reacting the copper and silver nitrate (AgNO3)
Pour sufficient silver nitrate solution into the test tube (pour sufficient solution to fill 3/4 of the test tube).
Put the test tube into the clamp and tighten the clamp. The test tube should be clamped near the top of the tube, but not right at the top.
Make sure the copper wire is longer than the test tube by about 2 cm. You need a handle projecting out of the test tube when it comes time to remove the copper wire. Place the copper wire into the silver nitrate solution. Watch the wire closely as it goes into the solution.
Allow the copper wire to sit in the silver nitrate solution undisturbed over night.
Cleaning the silver produced
Handle the wire by the exposed portion and shake off the silver (in an up-and-down motion) into the test tube. The silver will settle to the bottom.
Rinse any silver crystals the copper wire off into the beaker. Do not rinse off the wire into the sink or the test tube. Rinse only with distilled water. Set the wire aside on a paper towel and allow to air dry, then weigh it. Record the value in your data table.
Pour everything from the test tube, solution and silver, into the 150-mL beaker. Rinse all silver crystals into the beaker. When there seem to be no more silver crystals in the test tube, wash it one more time with distilled water. Set the test tube aside to dry.
Decant* the liquid in the beaker while keeping the solid silver in the beaker. Here is how:
• start the water gently running in the sink; it does not to be running hard.
•
hold a stirring rod in one hand and the beaker in the other. One person should decant, not two.
• slowly pour the liquid off while trying to keep the solid undisturbed.
do not pour off the last 5 mL of solution. In this manner, we will minimize the loss of solid during decanting. Please realize you will lose some solid, the point is to minimize it.
Add about 20 mL of distilled water to the silver, swirl and let the silver settle. Decant. Add another 20 mL of distilled water, swirl and decant.
Place your beaker under the heat lamps, as directed by the teacher.
Weighing the silver
When dry, remove from under the heat lamps, allow to cool off and weigh. Record the value in your data table.
Copper wire (before) _______________ g
Copper wire (after) _________________g
Empty beaker ______________ g
Beaker withy silver ___________g
* Decant means to pour off a liquid while the solid remains in the container
maybe this can help
silver nitrate
EQIPMENT NEEDED:
• Beaker
• Stirring rod
• Balance
• Test tube clamp
• Copper wire (clean it up with sand paper)
• Silver nitrate ( used silver nitrate is OK)
• Distilled water
Obtain one approximately 30-cm piece of copper wire. Coil it around a pencil. It should be an open coil and leave about 5 cm of wire uncoiled to act as a handle.
Use the electronic balance to weigh the copper wire coil. Make sure that none of the wire is touching the balance base. Record this value in your data table.
Make sure the test tube clamp is attached to the ring stand, about 10 cm down from the top.
Reacting the copper and silver nitrate (AgNO3)
Pour sufficient silver nitrate solution into the test tube (pour sufficient solution to fill 3/4 of the test tube).
Put the test tube into the clamp and tighten the clamp. The test tube should be clamped near the top of the tube, but not right at the top.
Make sure the copper wire is longer than the test tube by about 2 cm. You need a handle projecting out of the test tube when it comes time to remove the copper wire. Place the copper wire into the silver nitrate solution. Watch the wire closely as it goes into the solution.
Allow the copper wire to sit in the silver nitrate solution undisturbed over night.
Cleaning the silver produced
Handle the wire by the exposed portion and shake off the silver (in an up-and-down motion) into the test tube. The silver will settle to the bottom.
Rinse any silver crystals the copper wire off into the beaker. Do not rinse off the wire into the sink or the test tube. Rinse only with distilled water. Set the wire aside on a paper towel and allow to air dry, then weigh it. Record the value in your data table.
Pour everything from the test tube, solution and silver, into the 150-mL beaker. Rinse all silver crystals into the beaker. When there seem to be no more silver crystals in the test tube, wash it one more time with distilled water. Set the test tube aside to dry.
Decant* the liquid in the beaker while keeping the solid silver in the beaker. Here is how:
• start the water gently running in the sink; it does not to be running hard.
•
hold a stirring rod in one hand and the beaker in the other. One person should decant, not two.
• slowly pour the liquid off while trying to keep the solid undisturbed.
do not pour off the last 5 mL of solution. In this manner, we will minimize the loss of solid during decanting. Please realize you will lose some solid, the point is to minimize it.
Add about 20 mL of distilled water to the silver, swirl and let the silver settle. Decant. Add another 20 mL of distilled water, swirl and decant.
Place your beaker under the heat lamps, as directed by the teacher.
Weighing the silver
When dry, remove from under the heat lamps, allow to cool off and weigh. Record the value in your data table.
Copper wire (before) _______________ g
Copper wire (after) _________________g
Empty beaker ______________ g
Beaker withy silver ___________g
* Decant means to pour off a liquid while the solid remains in the container
Cheers Jazz
-
dolphinscales
- Posts: 370
- Joined: 30 Oct 2006, 10:00
- Job Title: Laboratory Technican
- School: Mandurah Senior College
- State/Location: WA
Thanks Jazz - it does not quite fit the needs - it needs to run over a few weeks so they can see the increase and decrease of growth.
i like the prac and will keep a copy of it should "they" decided on some thing a little more complex (in this case has too many instructions to follow) sigh!
thanks all the same Jazz - it is a nice prac.
Any one else
i like the prac and will keep a copy of it should "they" decided on some thing a little more complex (in this case has too many instructions to follow) sigh!
thanks all the same Jazz - it is a nice prac.
Any one else
Hi Dolphinscales
The following simple crystal prac was one of the activities at the Science SASS conference in St Marys in Sydney last November. Is this the kind of thing you're after?
CRYSTAL SNOWFLAKE - BORAX
Materials:
Borax, beaker, jar, food colouring, wire, paddle pop stick, white (cotton) pipecleaners.
Method:
* to 200ml water add 2 tblspns Borax (I had a go and thought 200ml not enough. 300ml with 3 tblspns Borax?)
* bring mixture to the boil and allow to boil for about 2 minutes
* add a few drops of food colouring and leave the solution to cool
* during this time the students can make their snow flake (or other) shape out of pipecleaners
* transfer the solution to a jar and gently add the snowflake frame into the solution, suspending it on a paddle pop stick. Make sure the jar has a wide neck so it can be easily removed.
* in a few days there are crystals. Leave as long as possible to build up a good snowflake. Great fun and less toxic than copper sulfate.
I hope this is more appropriate for your needs.
Julie
The following simple crystal prac was one of the activities at the Science SASS conference in St Marys in Sydney last November. Is this the kind of thing you're after?
CRYSTAL SNOWFLAKE - BORAX
Materials:
Borax, beaker, jar, food colouring, wire, paddle pop stick, white (cotton) pipecleaners.
Method:
* to 200ml water add 2 tblspns Borax (I had a go and thought 200ml not enough. 300ml with 3 tblspns Borax?)
* bring mixture to the boil and allow to boil for about 2 minutes
* add a few drops of food colouring and leave the solution to cool
* during this time the students can make their snow flake (or other) shape out of pipecleaners
* transfer the solution to a jar and gently add the snowflake frame into the solution, suspending it on a paddle pop stick. Make sure the jar has a wide neck so it can be easily removed.
* in a few days there are crystals. Leave as long as possible to build up a good snowflake. Great fun and less toxic than copper sulfate.
I hope this is more appropriate for your needs.
Julie
Hi Dolphinscales,
We use the following method to make small crystal gardens for the students. They are told what colours will come from which chemical, and then get to choose their own colours. Good luck with this.
YOU WILL NEED:
1) One small, clear container (100ml to 150ml) with a screw top lid.
2) A teaspoon of sand in the bottom and perhaps a small rock or pebble (to make it look more like a garden).
CHEMICALS USED:
Use crystals from any or all of the following chemicals to ensure a colourful and interesting garden:
Copper sulphate blue
Cobalt chloride red
Iron II Sulphate whiten
Iron III Chloride brown
Magnesium sulphate white
Nickel chloride green
Strontium nitrate red
Calcium chloride white
Aluminium Potassium Sulphate white
Solution of Sodium silicate (waterglass)
METHOD:
1 Write your name clearly on your container, AND on the lid.
2 Fill your container with the ‘waterglass solution (leave about 10cm from top).
3 Place the filled container on a flat surface, away from vibrations and bumps.
4 Carefully drop the crystals onto the bottom of the container. You may use forceps for this, but do NOT let them touch the solution.
5 Leave the crystals for 2–12 hours, although some may start to grow almost immediately.
6 The solution can be tipped off slightly to view the crystals which have formed.
7 The longer the crystals are left, the better they grow (about 1 week).
We use the following method to make small crystal gardens for the students. They are told what colours will come from which chemical, and then get to choose their own colours. Good luck with this.
YOU WILL NEED:
1) One small, clear container (100ml to 150ml) with a screw top lid.
2) A teaspoon of sand in the bottom and perhaps a small rock or pebble (to make it look more like a garden).
CHEMICALS USED:
Use crystals from any or all of the following chemicals to ensure a colourful and interesting garden:
Copper sulphate blue
Cobalt chloride red
Iron II Sulphate whiten
Iron III Chloride brown
Magnesium sulphate white
Nickel chloride green
Strontium nitrate red
Calcium chloride white
Aluminium Potassium Sulphate white
Solution of Sodium silicate (waterglass)
METHOD:
1 Write your name clearly on your container, AND on the lid.
2 Fill your container with the ‘waterglass solution (leave about 10cm from top).
3 Place the filled container on a flat surface, away from vibrations and bumps.
4 Carefully drop the crystals onto the bottom of the container. You may use forceps for this, but do NOT let them touch the solution.
5 Leave the crystals for 2–12 hours, although some may start to grow almost immediately.
6 The solution can be tipped off slightly to view the crystals which have formed.
7 The longer the crystals are left, the better they grow (about 1 week).
-
dolphinscales
- Posts: 370
- Joined: 30 Oct 2006, 10:00
- Job Title: Laboratory Technican
- School: Mandurah Senior College
- State/Location: WA
