Wednesday, May 12, 2010

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.

Tuesday, May 11, 2010

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."

Sunday, May 2, 2010