Colloid and Test Tube

Title of Experiment: Colloids and their Properties Experiment Number 2 Date: Dec. 6, 2010

Objective: To determine the properties of colloids and how they function in physiological systems

Materials:

O.1 M CuSO4 * 10% skim milk mixture 3 M HAc 0.2 M K2Cr2O7 0.04 M AgNO3 0.02 M K2Cr2O7 * 1% Gelatin 0.01 M AgNO3 5 Test tubes Dialysis bag

Observations:

Part I.

|Test Tube Number |CuSO4 Solution |Skim Milk |3 M HAc |
|1 |4 mL | | |
|2 | |4 mL | |
|3 | |4 mL |1 mL |

Question: In which tube/s is/are there evidence of curd-formation?

Answer: In test tube 1 and 2, there was no evidence of curd-formation but in test tube 3 there was an evidence of curd-formation

Part II.

Question: Which particles are large enough to be retained by the filter paper?

Observation: The curd-formation in test tube 3 is large enough to be retained by the filter paper.

Part III.

Observation: The CuSO4 from test tube 1 did not migrate through the dialysis bag. When light was held against it, the light passed through it. Test tube 2, the passage of skim milk was indicated by the turbidity outside of the dialysis bag and when light was held against it, the colloidal particles scattered the light.

PART V.

Observation: In test tube 1, the substance becomes heterogeneous mixture. In test tube 2, it has single phase because it remain as a colloid due to the addition of gelatin.

PART VI.