Final Post

I had to do this because I only had 17 posts and 17 is an ugly number.

Anyway, SRP report is over. Poster now?

As annoying as this was, I did learn a lot, not only about sucrose but also about getting things done early and the importance of planning. I'm glad I handed it in the day before it was due to save the heart-attack moments the next morning. Even if it did mean doing lots of work the day before.

Finished!!

I finished my report!!! Handing it in tomorrow (or I guess technically today). Did my booklet too :)

Sigh of relief.

References

Thought I would post these because I would've died trying to do this without them.

Bloomfield, L. (1998). How Everything Works. Retrieved June 13, 2010, from http://www.howeverythingworks.org/page1.php?QNum=1419.

Brotherton, J. & Mudie, K. (2000). Biology (4th ed.). Port Melbourne, Victoria: Reed International Books.

Chang, R. (1977).Physical Chemistry with Applications to Biological Systems (2nd ed.). New York: MacMillan Publishing Co., Inc.

Goode, S., Mercer, E., & Reger, D (1993). Chemistry: Principles and Practice. Orlando, Florida: Saunders College Publishing.

Helmenstine, A. (2009) Melting Snow and Ice With Salt. Retrieved June 2nd, 2010, from http://chemistry.about.com/cs/howthingswork/a/aa120703a.htm

Molecular Polarity (n.d.). Retrieved June 11th, 2010 from http://www.elmhurst.edu/~chm/vchembook/210polarity.html.

Refrigerators and Freezers (2005). Retrieved June 2nd, 2010 from https://energyaudit-sdge.sempra.com/library/refrfrez.asp.

Shlumberger, S. (2009) Why Does Salt Lower Freezing Point and Raise Boiling Point? Retrieved June 13th, 2010 from http://www.seed.slb.com/v2/faqview.cfm?id=1112.

The Solubility of the Sugars (2008). Retrieved June 11th, 2010 from http://chestofbooks.com/food/science/Experimental-Cookery/The-Solubility-Of-The-Sugars.html.

Sweetman, S. (2009). Martindale: The Complete Drug Reference (26th ed.). London: Pharmaceutical Press.

Zumdhal, S. (1993). Chemistry (3rd ed.). Lexington, MA: D.C. Heath and Company.

Results

(Y axis is meant to have a label saying "Temperature in degrees celsius" but I labelled it on my school computer rather than this one.

Method

This is the method I used today when conducting my experiment:

All necessary equipment was obtained from shopping centres and the household. 2.5 kilograms of sugar was split into parts of 1.5 kilograms and 1 kilogram and dissolved in 2 litres of H2O, split into parts of 1.5 litres (Solution C) and 0.5 litres (Solution A) respectively and 150 millilitres of each of these solutions was poured into measuring cylinders. Two more solutions were then made from these two basic solutions. Solution B was created from 75 millilitres of Solution A and 75 millilitres of Solution C and Solution D was created from 75 millilitres of Solution C and 75 millilitres of H2O. As a control, 150 millilitres of plain water was also used. Solutions A-D and the control were then poured into plastic cups. The plastic cups were then labelled.
The temperature of Solution A was measured using a probe thermometer and recorded.
The cup was then placed into a freezer of temperature -20OC. The temperatures of the control and of Solutions B-D were then measured and recorded and the cups placed in the freezer.
This process was repeated every 15 minutes until the solutions either froze or became too cold for the thermometer to measure. The equipment and materials were then cleaned up. The experiment was repeated.

Pictures!

Water Bottle containing saturated solution.

Examples of cups and labels.

All the cups lined up in a row. Notice the solutions become yellower as more sugar is added.

The measuring device containing the saturated solution.

The freezer they were put in.

The 25% saturated solution after the experiment was conducted.

The saturated solution after the experiment was conducted.

50% saturated solution after freezing.

The freezer space.

Risk Assesment

Identify: Thermometer probe is very sharp.
Assess: The probe could cut someone's hand.
Control: Hold thermometer by the display, put case on thermometer when not in use.
Disposal: Put case on thermometer at end of experiment.

Identify: Sugar solutions.
Assess: The solutions could go in someone's eye.
Control: Be very careful when handling solutions.
Disposal: Tip solutions down sink and wash away with warm water.

Identify: Ice.
Assess: Touching the ice for too long could harm someone.
Control: Close freezer, do not hold on to cups for too long after they have been frozen.
Disposal: Melt ice with warm water at the end of the experiment.

Thermometer

I finally found a thermometer that was suitable to use!!


http://www.dse.com.au/cgi-bin/dse.storefront/4c04a95402f24b1e2743c0a87e010624/Product/View/Y5118

I had to go all the way to Hurstville to get it.

SRP here I come!

Method For Sugar Experiment

Aim: To investigate whether the concentration of sugar in water has an effect on the freezing rate of water.

Materials: 4 x 200 mL water
400g sugar (to be split into three quantities of 66g, 134g and 200g)

Equipment:

• 4 plastic cups
• Freezer(set at -18°C)
• Timer
• Thermometer
  

Method:

1. Distribute materials into cups as follows:

• 1 x tap water
• 1 x tap water mixed with 66g of sugar
• 1 x tap water mixed with 134g of sugar
• 1 x tap water mixed with 200g of sugar

2. Measure the temperature of each of the solutions and alter temperature if needed to ensure a fair test.

3. Place all cups inside the freezer and begin timing.

4. Measure the temperature of the water at intervals, beginning with 20 minutes and decreasing as the solutions are near freezing point.

5. Record all data and observations.

6. Stop measuring once all 4 solutions have frozen.

7. Repeat steps 1-6 at least 3 times.

Variables

A list of variables for my sugar experiment:

Independent Variable:
1. The quantity of sugar in each cup.

Dependent Variable:
1. How long each solution will take to freeze.

Controlled Variables:
1. The temperature of the freezer.
2. Temperature of the solutions.
3. Amount of time the cups are in the freezer
3. Quantity of solutions in the cups.

Types of Sugar

During the experiment I will be using sucrose.

Sucrose is commonly known as table sugar. According to Wikipedia; "The molecule is derived from glucose and fructose with the molecular formula C₁₂H₂₂O₁₁."

According to http://www.3dchem.com/molecules.asp?ID=59, sucrose is a disaccharide; "Disaccharides are compounds that contain a bond between carbon(1) of one sugar and a hydroxyl group at any position on the other sugar.

Sucrose, ordinary table sugar, is probably the single most abundant pure organic chemical in the world and the one most widely known to nonchemists. Whether from sugar cane (20% by weight) or sugar beets (15% by weight), and whether raw or refined, common sugar is still sucrose."

Climate Graph

Useful Sites

http://www.worsleyschool.net/science/files/saltandfreezing/ofwater.html - explains about what happens to the molecules in the water during the freezing process.

http://www.newton.dep.anl.gov/askasci/env99/env133.htm - explains about ions in the water, info about crystal formation during the freezing process.

http://www.scienceproject.com/projects/intro/primary/PX071.asp - project.

http://en.allexperts.com/q/Oceanography-2135/salt-water-freezing-1.htm - explains from a chemistry-ish perspective why the salt water lowers the melting and freezing temperatures of the water.

http://www.picotech.com/experiments/freezingofwater/freezingofwater.html - experiment info.

Variables for Saltwater/Pure Water Experiment

If I were to go ahead with the freezing of saltwater vs pure water experiment, the variables would be as follows:

Independent Variables:
1. Amount of time in freezer
2. Quantity of water
3. Temperature of water
4. Salt/sugar/vinegar/nothing in water
5. Temperature of freezer

Dependent Variables:
1. How quickly the temperature drops
2. How quickly each of the cups of water freezes

Experiment - Using Water, Sugar, Salt and Vinegar

I think what would be best would be to do an experiment to investigate which of the following slows down the freezing of water best - sugar, salt or vinegar.

Just discovered this site - http://www.picotech.com/experiments/freezingofwater/freezingofwater.html.

It gives an example of an experiment used to test the freezing of salt water compared to the freezing of pure water.

The problems with the experiment on the website are:
1. The equipment listed is very complicated/unattainable - e.g. "DrDAQ DataLogger". BUT wouldn't a thermometer do the same thing?
2. Because of changing the equipment the experiment would be more confusing/difficult.

The other thing to consider would be how often to measure the temperature. Measuring would also have to be done very quickly in order for the results to not be affected by the room temperature.

Experiment Method I would use if I conducted this experiment:
1. Fill 4 plastic cups with plain tap water, water with sugar mixed in, water with salt mixed in and water with some vinegar in it.
2. Place each cup in the same freezer.
3. Measure the temperature of the solutions at specified intervals.
4. Record results.
5. Repeat experiment several times.

Salt/Sand

More on the idea of salt melting sand/preventing it from freezing.

According to http://van.physics.illinois.edu/qa/listing.php?id=1580, salt lowers the melting and freezing point of water.

This also means salt water will freeze more slowly than regular water. Maybe it would be better to do an experiment concerning salt and the freezing point of water than salt preventing sand from freezing.

Other sites also stated that, when water is frozen, the molecules lose energy and come closer together to form the hydrogen bonding required to form ice. However, when salt (an impurity) is in the way, the molecules need to lose more energy.

Ideas

1. Quick assessment of danger as related to age.

Best way to do this might be using photos. Saw something on the ABC once which was similar. People of various ages sorted pictures into dangerous/not dangerous piles and apparently teenagers got most many of them wrong. Lots of background research on that one. Not consistent enough?


2. Evaluate how much salt is needed to keep sand from freezing.

Saw something once about truck drivers in the US who, for some reason, were driving sand halfway across the country in freezing weather and their sand kept freezing. Apparently salt fixes this. Did some research and some people said 5% salt, some 50%. Could use different types of salt as well (some people suggested Potassium Chloride, some Calcium Chloride etc.).


3. If all else fails, generic "does music affect plant growth?" experiment is always available.

Hello World