Mystery+Powders

MYSTERY POWDERS White powder found at a crime scene or in a suspect's pocket may be an illegal substance or merely sugar. A detective will have the crime lab identify the substance to determine whether a crime has been committed. Try the following activity to learn how forensic scientists use chemistry to identify unknown substances. MATERIALS measuring spoon  baking soda  sugar  salt  cornstarch  white paper  black construction paper  white chalk  magnifying lens  eyedropper  water  4 small jars  iodine solution  <span style="color: #800000; font-family: 'Comic Sans MS',cursive; font-size: 140%;">dish towel  <span style="color: #800000; font-family: 'Comic Sans MS',cursive; font-size: 140%;">vinegar to Water || Reaction to Iodine || Reaction to Vinegar ||
 * || Appearance || Texture || Smell || Reaction
 * BakingSoda ||  ||   ||   ||   ||   ||   ||
 * Sugar ||  ||   ||   ||   ||   ||   ||
 * Salt

Cornstarch ||  ||   ||   ||   ||   ||   || <span style="color: #800000; font-family: 'Comic Sans MS',cursive; font-size: 140%;">PROCEDURE <span style="color: #800000; font-family: 'Comic Sans MS',cursive; font-size: 140%;">1. Put 1/2 teaspoon (1ml) of each white powder on a separate sheet of black construction paper. Use the chalk to label each powder. <span style="color: #800000; font-family: 'Comic Sans MS',cursive; font-size: 140%;">2. Examine each powder with the magnifying lens. What does each powder look like? What is its shape? Are its grains large or small? Record your observations in the Appearance column of the chart. <span style="color: #800000; font-family: 'Comic Sans MS',cursive; font-size: 140%;">3. Rub each powder between your fingers. How does it feel? Record comments in the Texture column. <span style="color: #800000; font-family: 'Comic Sans MS',cursive; font-size: 140%;">4. Do any of the powders have a smell? If so, record that information in the Smell column. <span style="color: #800000; font-family: 'Comic Sans MS',cursive; font-size: 140%;">5. Use the eyedropper to place a drop of water on each powder. What happens? Do any of the powders dissolve or react in any other way? Record the results in the Reaction to Water column. <span style="color: #800000; font-family: 'Comic Sans MS',cursive; font-size: 140%;">6. Put 1/2 teaspoon of each powder in a separate jar. Use the eyedropper to add 2 drops of iodine solution to each jar. Observe what happens and record your observations int he Reaction to Iodine column.