Display board

[luker]

Hi. I'm in 4th grade. I did my project on deicers. It was cool but now my brain hurts. I'm doing my science fair project display board but my research section is too long to fit without it being smaller than a 16 font or to scrunched up. Is it importnat to put it on the display? Should I try to shorten it for the display?
Thanks! The science fair is next week.
Luker

[barretttomlinson]

Hi Luker,

Have you read the Science Buddies Project Guide on display boards?

http://www.sciencebuddies.org/science-f ... oard.shtml

I would suggest condensing your background research section to summarize just the most important points. You can put a copy of your full research report, including your backfround research section in all irs full detail as a booklet on the table in front of your display board. A judge looking at your display must understand your whole project in less than five minutes looking at it from 3 to 5 feet away, so don’t make it hard for him/her to read by using small type or scrunching it up or he/she will just have to skip over it due to lack of time. Some of your judges may be getting middle aged eyes that can’t read very small type from a distance. (this is the voice of experience talking- I judged a fair last week!)

Good luck and have fun at the fair!

Best regards,

Barrett L Tomlinson.

[luker]

Yeah, I'm just confused because our science fair says I'm supposed to include all the parts like abstract and variables. I think I can put the background stuff in lists. I can make a list of four characteristics that affect deicers (freezing point depression, effective eutectic melting temperature, hygroscopic, exothermic) and then make other lists under each chemical for there characteristics (calcium chloride = 3 ions(particles), melting temp -29C, is hygroscopic and is exothermic). I took picturs of each of my chemicals under a micrscope and those will make cool headings.

Ok so whle I'm asking questions, I hate my results section. If I were a judge I would like reading it, but it says I'm supposed to tell what the numbers say. This is what I have..

In this experiment, the independent variable that was changed was the type of chloride compound used and the dependent variable was the amount of ice melt measured in milliliters. The types of chloride compounds used were sodium chloride, magnesium chloride, potassium chloride and calcium chloride. The average amount of melt at 0oC for each chloride compound was sodium chloride 8.3 ml, magnesium chloride 19.2 ml, potassium chloride 7.8 ml and calcium chloride 32.2 ml. (See Table 1) The average amount of melt at -6oC was sodium chloride 3.6 ml, magnesium chloride 16.2 ml, potassium chloride 3.8 ml and calcium chloride 25.2 ml. (See Table 2) The average amount of melt at -18oC was sodium chloride 1.1 ml, magnesium chloride 15.7 ml, potassium chloride 1.1ml and calcium chloride 25.2 ml. (See Table 3)

Across all three temperature sets, calcium chloride and magnesium chloride created more melt than sodium chloride and potassium chloride. Both are exothermic and are made up of three atoms, but sodium chloride and potassium chloride are not exothermic and are made up of only two atoms. Also, both clacium chloride and magnesium chloride had lower eutectic melting temperatures than sodium chloride and potassium chloride.

Got any suggestions?

If it helps this is what I have for a conclusion..
The hypothesis tested was that if sodium chloride, magnesium chloride, potassium chloride and calcium chloride are applied to ice at temperatures of 0°C, -6°C and -18°C, then calcium chloride will on average melt ice the fastest at each temperature.
It was found that although the amount of melt decreased as the temperature decreased for all the chloride compounds, in all three temperature sets calcium chloride on average melted more ice in the twenty-minute time period than the other chloride compounds tested. (See Graph 1) Therefore, the data tends to support the hypothesis.

THANKS!!!
luker

[barretttomlinson]

Hi,

Your text looks fine to me. My only comment - would it make sense to present your results in a table?

Have fun at the fair!

Barrett L Tomlinson

[barretttomlinson]

Hi Luker,

One more thing occurred to me - you did not mention “colligative properties” in your posting. You may want to investigate them before your science fair if you have not heard about them. Colligative properties are properties like freezing point depression that depend only on the number of particles present in solution, not on the particular chemical properties of the particles. They are discussed in this Science Buddies Project Idea on freezing point depression:

http://www.sciencebuddies.org/science-f ... p049.shtml

Pay particular attention to the links in the Bibliography section of the writeup for more explanation.

You did not say if you applied equal amounts (weights?) of your test salts to a fixed amount of ice in running your tests. If you did it might be interesting to compute the relative number of ions in the fixed amounts of salts you used (weight of salt/molecular weight of salt)*number of ions per molecule of salt = Moles of ions. It would be interesting to know if this number was proportional to the amount of water melted in your fixed time interval.

I am just curious - I really do not know what the answer “should be”

Best regards,

Barrett L Tomlinson

[luker]

I had learned about colligative properties and put that in my science paper. I read about mole but I didn't understand them. I tired what you said, but can you tell me for sure what you mean in your equation for the weight of salt? I used 10 grams of each chloride compound in my experiment. So here's what I did for NaCl
(10g/58.44)x2=0.3422 moles of ions. If I did it right then what I learned was that MgCl2 has more moles of ions (0.502)than CaCl2 (0.3972) but CaCl2 had more melt. NaCl and KCl were about the same and made about the same melt. So what I wonder is if moles of ions has less to do with the melt than the exothermic heat. CaCl2 got really hot when I mixed it with water but MgCl2 got only a little warm. Do you have any suggestions for how to measure exothermic reactions?
THANKS!!! And thanks a bunch for help on the mole thing!