Classification of Matter Lab Name
Classification of Matter Lab
Name _________________________________
Working with Pure Substances
Lab partner(s) __________________________
Forming and Separating Compounds Using Chemical Processes Background All pure substances have a constant composition that can be represented using a chemical formula. For a compound, a chemical formula is a set of chemical symbols showing the elements present and their relative proportions. All events follow the Law of Conservation of Mass (also called the Law of Conservation of Matter). In lab you will first combine elements to form the compound magnesium oxide and 2nd separate the compound copper (II) sulfate into its constituent parts. During lab both qualitative and quantitative data will be collected. Each person must have their own copy of the data. Next class this data will be used in calculations to determine the percentage composition of each compound and the percent error for this lab. Investigation #1 Formation of Magnesium Oxide magnesium (s) + oxygen (g) magnesium oxide (s)
Prior to Starting
Practice using the crucible tongs to pick up the crucible and lid. Practice placing the lid partially over the crucible so that there is a gap.
Procedure 1. Obtain a clean dry crucible and lid. 2. Obtain about 35mm of magnesium ribbon. The ribbon must be clean. 3. Fold (coil) the ribbon to fit into the bottom of the crucible. Then mass the crucible, lid and magnesium ribbon.
4. With the cover off, heat the crucible. Increase the temperature gradually. When the magnesium ribbon glows red, or ignites, cover the crucible quickly and reduce the amount of heat applied. After about a minute remove the cover (to let in more oxygen) and heat until you observe the magnesium glowing or igniting. Then replace the cover and reduce the heat. Continue this procedure until no further reaction (igniting) occurs. Then tilt the cover, and heat strongly for a few minutes. Let the crucible cool. 5. When the crucible is cool, remove the cover. Use a stirring rod to grind the contents of the crucible into small particles. Rinse the particles remaining on the stirring rod into the crucible with about ten drops of distilled water. Replace the cover, leaving a small opening. Heat gently until the water begins to boil. The water is added to convert any magnesium nitride that might have formed during the reaction to magnesium oxide. Remove the burner, and waft the vapor to see if it has any odor. Then, continue heating until the residue is thoroughly dry. 6. When the crucible, lid and magnesium oxide are cool take a final mass measurement. Be sure to use the same balance used in Step 1. 7. Products of this reaction should go in the waste beaker found in the fume hood. 8. Thoroughly wash and rinse all equipment and return original location. Clean your bench and work area. 9. Wash your hands before leaving lab.
Name _________________________________
Working with Pure Substances
Lab partner(s) __________________________
Forming and Separating Compounds Using Chemical Processes Background All pure substances have a constant composition that can be represented using a chemical formula. For a compound, a chemical formula is a set of chemical symbols showing the elements present and their relative proportions. All events follow the Law of Conservation of Mass (also called the Law of Conservation of Matter). In lab you will first combine elements to form the compound magnesium oxide and 2nd separate the compound copper (II) sulfate into its constituent parts. During lab both qualitative and quantitative data will be collected. Each person must have their own copy of the data. Next class this data will be used in calculations to determine the percentage composition of each compound and the percent error for this lab. Investigation #1 Formation of Magnesium Oxide magnesium (s) + oxygen (g) magnesium oxide (s)
Prior to Starting
Practice using the crucible tongs to pick up the crucible and lid. Practice placing the lid partially over the crucible so that there is a gap.
Procedure 1. Obtain a clean dry crucible and lid. 2. Obtain about 35mm of magnesium ribbon. The ribbon must be clean. 3. Fold (coil) the ribbon to fit into the bottom of the crucible. Then mass the crucible, lid and magnesium ribbon.
4. With the cover off, heat the crucible. Increase the temperature gradually. When the magnesium ribbon glows red, or ignites, cover the crucible quickly and reduce the amount of heat applied. After about a minute remove the cover (to let in more oxygen) and heat until you observe the magnesium glowing or igniting. Then replace the cover and reduce the heat. Continue this procedure until no further reaction (igniting) occurs. Then tilt the cover, and heat strongly for a few minutes. Let the crucible cool. 5. When the crucible is cool, remove the cover. Use a stirring rod to grind the contents of the crucible into small particles. Rinse the particles remaining on the stirring rod into the crucible with about ten drops of distilled water. Replace the cover, leaving a small opening. Heat gently until the water begins to boil. The water is added to convert any magnesium nitride that might have formed during the reaction to magnesium oxide. Remove the burner, and waft the vapor to see if it has any odor. Then, continue heating until the residue is thoroughly dry. 6. When the crucible, lid and magnesium oxide are cool take a final mass measurement. Be sure to use the same balance used in Step 1. 7. Products of this reaction should go in the waste beaker found in the fume hood. 8. Thoroughly wash and rinse all equipment and return original location. Clean your bench and work area. 9. Wash your hands before leaving lab.
