3-8-11 practical Artificial intestines

Procedures
Test for Starch

1. Place 1cm^3 of the unkown sample in the test tube
2. Add a few drops of iodine solution
3. Shake well
4. If starch is present, the solution in the test tube will turn blue-black
5. If starch is absent, the content in the test tube will be yellowish

Test for Reducing Sugars

1. Place 2cm^3 of the unknown sample in a test tube
2. Add 2cm^3 of Benedicts Solution
3. Place the test tube in a beaker of boiling water
4. If reducing sugars is present, a precipitate will form, and will turn from yellow to orange to brick red

*If reducing sugars is absent, the content of the test tube will be blue
Factors that Affect Solubility

• Temperature
• Nature of Solute (Sugar, Salt)
• Nature of Solvent (Water, Oil)
• Rate of dissolving
• Rate of Stirring
• Temperature of Solution
• Size of solute particles