Chemical and Physical Changes Lab
09/09/13
I. Purpose: Identify the different changes as a physical change or a chemical change.
II. Safety: You may need safety goggles and gloves.
III. Pre-lab questions: 1. Identify the following as either chemical or physical changes: a. Striking a match Chemical b. Food spoiling Chemical c. Breaking a glass Physical d. Mowing the grass Physical e. Leaves decaying Chemical f. Boiling water Physical
2. In your own words, state the Law of Conservation of Mass. Mass cannot be created or destroyed.
3. List the indicators of a chemical change. Energy change, such as endothermic and exothermic reactions, production of a gas (fizzing or bubbling), a formation of a precipitate, or an unexpected color change.
4. Identify each as an element, compound, or mixture. a. Air Mixture b. Sulfur Element c. Hydrogen gas Compound d. Salad Mixture e. Water Compound f. Sodium bicarbonate Compound g. Fruit punch Mixture h. Sodium chloride (table salt) Compound
IV. Procedure: Draw a 3 by 8 data chart using a ruler. Label one column with “experiment number”, one column to record the mass and observations, and one to label the experiment as a physical or chemical change. For experiment 1, combine iron fillings and sulfur powder on paper. Examine it with a magnifying glass. Then put a magnet under the paper and record any observations. For experiment 2, fill a beaker half way with cold water. Add contents of the test tube from the warm water bath into the beaker. Record any observations. For experiment 3, put a piece of magnesium in a test tube. Then add 10 drops of 6M HCl. Check for any temperature