10/16/12
Physical and Chemical Changes Lab
Question: How do you distinguish a physical and chemical change?
Hypothesis: If we use these materials and use magnets, water, burners, and filters on the mixtures and elements given we should determine what kind of effect these materials given will have on these mixtures and elements, physical or chemical.
Procedures:
-Part A: Record all observations of Part A in Data Table 1 1. Label each substance on seven pieces of paper. Put two pieces of magnesium ribbon on the paper labeled “Magnesium”. 2. Examine each substance with a magnifying glass. Record observations in Data Table 1. 3. Test the effect of a magnet on each substance by passing the magnet under the paper. 4. Test the solubility of each substance by mixing small amounts in a separate test tube with 3mL of distilled water in it, then “flick” each tube to mix the contents. 5. Return strip of magnesium in test tube to its paper. Follow teacher’s instructions for paper disposal of other materials.
-Part B: Record all observations of Part B in Data Table 2 6. Mix iron filings and sulfur on clean paper. Examine mixture with magnifying class. Test effect of magnet. Give this mixture to teacher for further use in Part C. 7. Mix sodium chloride and sand on clean paper. Examine mixture with magnifying glass and test effect of magnet. 8. Transfer salt-sand mixture into 100mL beaker, then add 30mL of water and stir. Record observations, and then prepare for filtration setup. Filter the mixture and record observations. Pour 10mL of filtrate into evaporating dish, then prepare burner to heat evaporating dish. Heat dish till filtrate is completely evaporated. Examine both dry residue in dish and wet residue on filter paper. 9. Caution: Do not look directly at burning magnesium. Using tongs pick up the magnesium and hold it over the burner till it ignites. After ignition quickly put burning magnesium over