Question

Procedure

1. Water as a universal solvent

a. Put about 0.5 grams of the following substances into six separate test tubes: NaCl, sugar, gelatin, margarine, ethanol.

b. Add 1 mL water to each test tube and shake vigorously to dissolve the substance. To substances that did not dissolve, add another 1 mL of water and shake again. Add another 1 mL to the solids that still not dissolve and shake again.

c. Repeat the solubility test using acetone instead of water.

2. Water as a good medium for biochemical reactions

a. Mix about 0.1 gram of dry, powdered citric acid and sodium bicarbonate (NaHCO3) in a dry test tube. Observe if a chemical reaction occurs.

b. Add about 10 mL of water to the mixture and note what happens

I. Find the solubility in WATER and solubility in ACETONE of the following:

1. NaCl

2. Sugar

3. Gelatin

4. Margarine

5. Ethanol

II. What are the reaction of Citric Acid and Sodium Bicarbonate?

Answer 1

In the presence of water, citric acid and sodium bicarbonate (aka baking soda) react to form sodium citrate, water, and carbon dioxide.