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"How do Crystals Form?"
Transcript of "How do Crystals Form?"
I chose this topic because I am interested in minerals and crystals, and I thought this would be fun. I think that certain substances will form crystals faster than others. One bottle of alum (aluminum potassium sulfate, a pickling spice)
One container of salt, One container of sugar
Very warm or hot water 500-mL beaker or glass measuring cup
Three large glasses or jars (that can hold at least 12 ounces)
Six coffee stirrers or craft sticks
Three pipe cleaners
Three eight-inch pieces of string
Three stickers or pieces of masking tape and a pen 1- Put on your disposable gloves and fill the beaker or measuring cup with 400 mL of hot water.
2- Sprinkle a little alum in the water and stir it with one of the stirrers until it dissolves completely. (Safety note: alum is a skin and eye irritant; always use gloves when you handle it, and don’t let it get in your eyes!)
3- If all of the alum dissolves, add a little more and stir again.
4- Keep doing this until it won’t dissolve any more. Now you have a saturated solution.
5- Make a circle out of one of the pipe cleaners, small enough to fit into one of the glasses without touching the sides, and tie it to a fresh stirrer with one of the pieces of string.
6- Set the stirrer across the top of the glass so the pipe cleaner dangles inside.
7- Write “Alum” on your sticker or tape and stick it to the outside of the glass.
8- Carefully pour the alum solution over the pipe cleaner and set the glass where nobody will disturb it and it won’t get too warm (you don’t want the water to evaporate too fast).
9- Wash the beaker or measuring cup thoroughly. Repeat steps 1-8 with the salt and then the sugar, using a fresh stirrer each time and labeling each solution as appropriate. Control - Unaltered Water
Variables – Container, Popsicle Stick, String
Manipulated Variable – Water, Pipe Cleaner To find out if some minerals form crystals faster or more easily than others What minerals can be put into saturated solutions to form crystals over time? Background Research 2 http://bitesizedbiology.tumblr.com/post/5184671665/adventures-in-growing-sugar-crystals
Tips on growing better sugar crystals:
-Use really hot water
-use a ton of sugar
-coat the string in sugar to jump-start the nucleation process
-cool down the water very slowly, to give the ctystals more time to grow. Background Research 3 http://www.buzzle.com/articles/sugar-crystals.html
The chemical formula of sucrose (cane sugar) is C12H22O11
Some good tips on growing good sugar crystals:
-Cover jar with wax paper
-put a weight on the string
-"seed" the string Background Research 4 http://www.sciencecompany.com/-W147.aspx
Crystal growing tips:
-The chemical or substance you're using to grow crystals should be pure.
-The water should be pure too. Use distilled water instead of tap water.
-The cup, bowl, or dish should be clean and "used". New glassware doesn't have any places for the crystals to nucleate. http://www.homepages.ucl.ac.uk/~ucfbanf/general/crystal.htm
Other household products that can be used to grow crystals are: Epsom salt, potash alum, chrome alum, fruit sugar (fructose), and cream of tartar. Background Research 5 http://www.ccmr.cornell.edu/education/ask/index.html?quid=742
When salt is dissolved in water, the sodium and chlorine atoms in the salt start to separate. When the water starts evaporating, the atoms re-combine and form solid, visible, salt crystals. Salt - Did O.K. Did not see any crystals until a couple days after the experiment started. Most crystals formed where the string was tied to the popsicle stick. Sugar - Did horrible. No crystals formed whatsoever. This experiment would be helpful to scientists to better understand how crystals grow in water. Thank you
for viewing my presentation!!! Conclusion To summarize, I found that the alum grew best, the salt didn't do well at first, but then grew in a place I didn't expect, and the sugar did not grow at all.
My hypothesis was correct. The alum grew faster and better than the other two substances.
If I were to do things differently, I would: 1) use chrome alum so that the crystals would be purple. 2) heat the water to a higher temperature. and 3) saturate the water even more. Bibliography "ASK! Options." CCMR. N.p., n.d. Web. 11 Jan. 2013.
"Bite-Sized Biology." - Adventures in Growing Sugar Crystals. N.p., n.d. Web. 11 Jan. 2013.
"Crystal Growing Definitions and Tips." Crystal Growing Definitions and Tips. N.p., n.d. Web. 11 Jan. 2013.
"Crystal Growing." Dom's Crystal Growing Page. N.p., n.d. Web. 11 Jan. 2013.
Nakate, Shashank. "Sugar Crystals." Buzzle.com. Buzzle.com, 01 Mar. 2010. Web. 11 Jan. 2013.