How to Test Household Compounds

Many simple over-the-counter pain medications are chemical compounds.

Household compounds are a combination of chemicals, found on the periodic table, that used in everyday living. A chemical compound, in general, is a substance formed by chemical union. It may not be obvious at first, but as you look at ingredient labels, you will see that many household products are chemical compounds. Some of the most common are table salt, baking soda, calcium supplement tablets or antacid tablets.

Things You'll Need

• Household compounds
• Water
• Measuring spoons
• Small glass cup
• Metal spoon
• Eye dropper
• Iodine
• White vinegar

Instructions

Test for Solubility

1. Measure 2 teaspoons of water in a clean glass cup.

2. 

   Test compounds once they are dissolved in water.

   Choose the household compound you would like to test and put a small pea-size amount of the compound in the measured water.

3. 

   A stainless-steel spoon is the best option for stirring. To eliminate additional chemical reactions, don't use zinc or copper spoons.

   Stir the compound in the glass with a metal spoon with the water for 5 minutes. If the mixture becomes clear after stirring, the compound is soluble; if the mixture is cloudy the compound is partially soluble; if the mixture is very cloudy with particles settling after stirring, the compound is insoluble.

Simple Tests to Determine Chemical Makeup

1. Measure 2 teaspoons of water in a clean glass cup.

2. 

   Starches added to household compounds, which naturally include polysaccharides, are often added to help powders pour easily.

   Add a small pea-size amount of the chosen compound to the glass.

3. 

   The color of the mixture containing a polysaccharide will be either a bright blue or a dark purple.

   Add 2 drops of iodine to the glass with the eye dropper and stir for five minutes. If the mixture is yellowish-brown, the compound does not contain polysaccharides. If it turns purple, the compound contains amylose. If it turns blue, it contains amylopectin. Amylose and amylopectin are polysaccharides.

4. 

   The carbon dioxide formed from the mixture of acetic acid, or vinegar, and sodium bicarbonate is released as a gas in bubbles.

   Using a clean glass add the compound and 1/4 teaspoon of white vinegar. If bubbling occurs, the compound contains sodium bicarbonate and is undergoing a chemical reaction by creating carbon dioxide.

Tips & Warnings

• Compounds that dissolve in water are experiencing a physical reaction not a chemical reaction. Therefore, if the water evaporated the original compound would be recovered.

• Compounds that experience a change in makeup are undergoing a chemical reaction and will need additional chemical reactions to recover their original state.

• A compound that experiences a chemical reaction often also undergoes a physical reaction. The reverse is rarely true.

• Do not taste the compounds.

• Make sure to clean the glass thoroughly before drinking out of it again.

References

• Mercer: Chemistry 111-112
• Princeton: WordNet Search, Chemical Compound

Resources

• MadSci Network: Why Does Starch Turn Iodine Solution Blue/Black
• Web Elements: Chemical Reactions of the Elements