Purpose The purpose of this lab is to distinguish the difference between physical and chemical properties and changes. Background A physical property is a characteristic of matter that can be changed without changing the mater’s composition. Examples include the odor of a substance, the color, its volume, its state of matter, density and melting and boiling points. A chemical property is a characteristic that determines how the composition of matter changes as a result of contact with other matter or the influence of energy. It is a characteristic that describes the behavior of matter. These include flammability, burning, rusting and toxicity. A physical change changes the form of a substance, but not its chemical composition. Physical changes …show more content…
Investigation H: During this investigation, the following changes were noted: the two solutions foamed and bubbled, and basically “exploded” outside of the graduated cylinder. Conclusion The purpose of this lab is to observe the differences between physical and chemical properties and physical and chemical changes. To test these differences, we conducted different experiments and concluded whether the reaction was a physical or chemical change. Investigation A: The chlorine from the copper chloride combined with the aluminum foil to create aluminum chloride. The dark substance left on the bottom of the beaker was copper. An exothermic reaction occurs, causing the temperature of the beaker to increase. It is a chemical reaction because two new substances are formed: copper and aluminum chloride. The chemical composition is changed, meaning the chemical formula changed from 3 CuCl2 + 2 Al to 2 AlCl3 + 3 Cu (David’s Digital Portfolio). Investigation B: NaCl is soluble in water, which caused the salt to dissolve into the water. It is a physical reaction because evaporating the water leaves the salt …show more content…
When the penny was placed in the flame of the bunsen burner, the copper melted and revealed the zinc, so it changed from a copper-color to silver. The color change is an example of a physical property, while the whole reaction is a chemical change. Investigation D: The magnesium reacts with oxygen in the air, and the bunsen burner is a source of heat for the reaction. When this reaction occurs, Magnesium Oxide is formed, making it a chemical change. Investigation E: Copper(II) sulfate is soluble in water. Through evaporation, the water and crystals can be separated, making this a physical change. Investigation F: Lead (II) nitrate and potassium iodide solution (KI) formed potassium nitrate and lead iodide, which is yellow precipitate. This is a chemical change because two new substances were