Professor Vinh Hoang
CHEM 1151L – 254
25 October 2013
Preparation of Viscous Solution
This report discusses an experiment to study the relationship of solute/solvent and the calculations involved to measure the concentration of the solution. The first experiment to take place is the preparation of a salad dressing using xanthan gum solution, water and oil. Commonly used as a food thickening agent, Xanthan gum is a large molecule composed of several saccharides linked together. The second experiment to be conducted is with the reagents polyvinyl alcohol and sodium borate solutions, each solution is to be added DI water to dissolve the solute then mixing both together at a breakthrough point temperature for the formation of a polymer – slime.
In the first experiment, into two small vials 1.00 mL of DI water and 1.00 mL of salad oil was added to each vial. For the preparation of the xanthan gum solution, 30.0mL of DI water was poured into a small beaker. The beaker was placed on a hot plate. A digital thermometer was used to measure the temperature of the DI water. Once its temperature reached to 50ºC, the DI warm water was then poured slowly in a different beaker containing 0.1513g of xanthan gum powder. The solution had been stirred for approximately four minutes when a moderate to high change in the water viscosity was noticeable, somewhat like a gel. The color of the solution remained clear and the powder did not dissolve completely as small particles of xanthan gum could be seen resting in the bottom of the beaker.
In one of those oil-in-water vials prepared, 1.00 mL of the xanthan gum solution was added while in the other vial, 1.00 mL of DI water was added to it. The next step was to shaken both vials. In the vial which the xanthan gum solution was added to the oil-in-water concentration, a change to the physical property of the solution took place. When agitated the solution viscosity decreased by creating small droplets of