Lab Report: Physical and Chemical Changes The purpose of this lab is to invest time into understanding the difference between a chemical and physical change by performing an experiment. In this lab, examples such as calcium carbonate, water, iron filings and sulfur, etc. were showcased to investigate a type of change and the reasoning for the change. Therefore, I want to ask the question: How can you determine a physical change from a chemical change? In my hypothesis, I believe that: If a substance performs a physical change, then most of the substance’s original properties will stay the same because it does not become a new substance. Additionally: If a substance performs a chemical change, then the substance’s original properties will change because it becomes a new substance. For the variables, I wasn’t sure if there was any since none were listed in the header of the student guide. But, if there is any: then, this is what I think they might be. Independent Variable: ● ● ● ● ● ● ● ● Step Two: Calcium Carbonate Step Three: powder formation of Calcium Carbonate Step Four: water Step Five: copper sulfate pentahydrate Step Six: iron filings and sulfur Step Seven: potassium iodide and lead nitrate Step Eight: hydrochloric acid Step 9: candle Dependent Variable: ● ● ● ● ● ● ● ● Step Two: N/A Step Three: hydrochloric acid Step Four: the boiled water Step Five: the final result of copper sulfate pentahydrate being heated up Step Six: the mixture of iron filings and sulfur Step Seven: the combination of potassium iodide and lead nitrate Step Eight: magnesium strip Step 9: the melted candle Controlled Variables: ● ● ● ● ● ● ● ● Step Two: Mortar and Pestle Step Three: N/A Step Four: hot plate Step Five: Bunsen burner Step Six: magnet Step Seven: N/A Step Eight: thermometer Step 9: the lit match Materials: ● ● Calcium Carbonate Mortar and Pestle ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● Spoon 100mL Beaker Hot Plate Hot Pad Copper Sulfate Crucible Crucible tongs Clay Triangle Tripod Bunsen Burner Iron Fillings Sulfur Petri dish Graduated Cylinder Magnesium Ribbon Thermometer Magnet Tweezers Potassium Iodide Lead Nitrate Candle Match Procedure: Step One: Gather Materials for each step. Step Two: Calcium Carbonate. (Materials: 2 inch piece of calcium carbonate, 25 mL 1M hydrochloric acid, mortar and pestle, spoon, 50 mL, and a beaker.) ● ● ● Place a 2-inch piece of calcium carbonate (from chalk) in a mortar. Crush the calcium carbonate with the pestle. Record all changes observed, the type of change, and your reasoning in the data table. Keep for Step 3 Step Three: Calcium Carbonate and Hydrochloric Acid. (Materials: same as step two.) ● ● ● ● Pour approximately 25 mL of 1M hydrochloric acid into a 50 mL beaker. Use the spoon to add crushed calcium carbonate from Step 2 to the hydrochloric acid. Record all changes observed, the type of change, and your reasoning in the data table. When finished, dispose of the mixture by pouring it into a receptacle provided by your teacher. Step Four: Water (Materials: 40 mL water, 100 mL beaker, hot plate, and a hot pad.) ● ● ● ● ● Fill a 100 mL beaker with 40 mL of water. Note its physical characteristics. Using a hot plate, heat the water until it boils. Record all changes observed, the type of change, and your reasoning in the data table. Use the beaker tongs to remove hot beaker from hot plate and place on a hot pad. Turn off the hot plate and dispose of the water in a drain Step Five: Copper Sulfate Pentahydrate (Materials: 2 g copper sulfate pentahydrate, spoon, crucible, crucible tongs, clay triangle, tripod, and a Bunsen burner.) ● To allow heating, place the clay triangle on top of the tripod and position the Bunsen burner under the tripod. ● ● ● ● ● ● Measure 2 g (approximately 1/2 tsp.) of copper sulfate pentahydrate in a crucible. Note its physical characteristics. Place the crucible on the clay triangle. Turn the Bunsen burner on to heat the crucible to see a change happen. Record all changes observed, the type of change, and your reasoning in the data table. Use crucible tongs to remove crucible from clay triangle and let cool. When cooled, dispose of copper sulfate powder into the receptacle provided by your teacher. Step Six: Iron Fillings and Sulfur (Materials: 1 spoonful iron filings, 1 spoonful powdered sulfur, spoon (2), petri dish, and a magnet.) ● ● ● ● Measure 2 g (approximately 1/2 tsp.) iron filings on the one side of a petri dish. Note the physical characteristics of the iron filings. Measure 2 g (approximately 1/2 tsp.) of sulfur on the other side of a petri dish. Note the physical characteristics of the sulfur. Mix the two materials with the spoon. Note the physical characteristics of the resulting mixture. Run a magnet over the resulting mixture, but do not allow the magnet to touch the mixture. Record all changes observed, the type of change, and your reasoning in the data table. ● Place the iron filings and sulfur separately into receptacles provided by your teacher. ● Step Seven: Potassium Iodide and Lead Nitrate (Materials: 25 mL 0.1M potassium iodide, 10 mL 0.1M lead nitrate, 50 mL beaker, and a 25 mL graduated cylinder.) ● ● ● ● ● Fill a 50 mL beaker with 25 mL 0.1M potassium iodide. Measure 10 mL of 0.1M lead nitrate into a 25 mL graduated cylinder. Pour lead nitrate into the potassium iodide slowly. Record all changes observed, the type of change, and your reasoning in the data table. Dispose of the mixture in the receptacle provided by your teacher. Step Eight: Magnesium and Hydrochloric Acid (Materials: 25 mL 1M hydrochloric acid, 3 cm magnesium ribbon (2), 50 mL beaker, thermometer, and tweezers.) ● ● ● ● ● ● Fill a 50 mL beaker with approximately 20 mL of 1M hydrochloric acid. Use a thermometer to measure the temperature of the hydrochloric acid in °C. Use tweezers to drop the two 3 cm magnesium ribbons in the hydrochloric acid. Measure the temperature of the solution again. Record all changes observed, the type of change, and your reasoning in the data table. (Be sure to consider the change of temperature!) Following your teacher’s instructions, dispose of the mixture in a filter set-up provided by your teacher. Step Nine: Candle (Materials: 1 candle on dish and matches.) ● ● ● ● ● Clear the area of flammable materials. Place the candle on a dish so that it is firmly on it. Use a match to light the candle. Let it burn for approximately 1 minute. Record all changes observed, the type of change, and your reasoning in the data table. Blow out the candle and put the candle and matches in receptacles provided by your teacher. Groups: Experimental Group: ● Step Two: powder formation of calcium carbonate ● ● ● ● ● ● ● Step Three: a mixture of hydrochloric acid and calcium carbonate Step Four: boiling water Step Five: white formation of copper sulfate pentahydrate Step Six: a mixture of iron filings and sulfur that is separated by a magnet Step Seven: a mixture of potassium iodide and lead nitrate Step Eight: heated up hydrochloric acid Step 9: melted candle Control Group: ● ● ● ● ● ● ● ● Step Two: calcium carbonate Step Three: powder formation of calcium carbonate Step Four: water Step Five: blue formation of copper sulfate pentahydrate Step Six: iron filings and sulfur Step Seven: potassium iodide and lead nitrate Step Eight: hydrochloric acid Step 9: candle Experiments Changes Observed Type of Change Reasons Calcium Carbonate The calcium carbonate was placed into a mortar where it was crushed up into powder by the pestle. physical even though a particle size change was observed, the calcium carbonate retained original form Calcium Carbonate And Hydrochloric Acid The powder form of calcium carbonate from the previous step was poured into a beaker filled with 1.0 M of Hydrochloric Acid. This mixture caused the liquid to bubble. chemical gas formation was observed, which indicated that the calcium carbonate was transformed into a different substance Water A beaker filled with water was placed on a hot plate. This caused the water to boil and steam was released from the beaker. physical even though the gas formation was observed, the water was undergoing a state change, which means that its original properties are preserved Copper Sulfate Pentahydrate Copper sulfate pentahydrate was heated above a Bunsen burner. This caused the substance to change from a blue color to a white color. A gas formation was also observed. chemical gas formation was observed along with a color change, which indicated that the copper sulfate pentahydrate was transformed into a different substance Iron filings and Sulfur Iron filings and sulfur were mixed together, forming a dark green color. When a magnet was placed above the mixture, the iron fillings were lifted to the magnet and separated from the sulfur. physical even though a color change occured, each solid maintained its original properties, which could be seen as soon as the magnet was applied Potassium Iodide and Lead Nitrate 0.1 M of Lead Nitrate was poured into 0.1 M of Potassium Iodide. This caused the Nitrate to immediately change colors and ultimately cause the potassium iodide to change colors as well. The two were not mixed. chemical both a color change and solid formation were observed, which provide strong evidence of a new substance Magnesium and Hydrochloric Acid When a magnesium strip was placed into hydrochloric acid, it caused the hydrochloric acid to heat up. chemical a temperature change occurred, a solid disappeared, and a gas was produced Candle When light was added to the candle, it caused the wax to melt. both physical and chemical physical because the wax melted and changed shape. chemical because light and heat were formed as the candle burned Final Analysis In step two (experiment one), the calcium carbonate was placed into a mortar where it was crushed up into powder by the pestle. This showcased a physical change because the calcium carbonate maintained it original form despite the change in size. In step three (experiment two), the powder form of calcium carbonate from the previous step was poured into a beaker filled with 1.0 M of Hydrochloric Acid. This mixture caused the liquid to bubble. This showcased a chemical change because a gas formation was observed and the calcium carbonate changed as a substance. In step four (experiment three), a beaker filled with water was placed on a hot plate. This caused the water to boil and steam was released from the beaker. This showcased a physical change because the water maintained its original form despite an observation of a gas formation. In step five (experiment four), copper sulfate pentahydrate was heated above a Bunsen burner. This caused the substance to change from a blue color to a white color. A gas formation was also observed. This showcase a chemical change because a color change and gas formation was observed which cause the copper sulfate pentahydrate to change from its original properties. In step six (experiment five), iron filings and sulfur were mixed together, forming a dark green color. When a magnet was placed above the mixture, the iron fillings were lifted to the magnet and separated from the sulfur. This showcased a physical change because the iron filings and sulfur maintained their original form despite an observation of color change. In step seven (experiment six), 0.1 M of Lead Nitrate was poured into 0.1 M of Potassium Iodide. This caused the Nitrate to immediately change colors and ultimately cause the potassium iodide to change colors as well. The two were not mixed. This showcased a chemical change because both a color and solid formation change were observed. In step eight (experiment seven), a magnesium strip was placed into hydrochloric acid which caused the hydrochloric acid to heat up. This showcased a chemical change because a temperature change occurred, a solid disappeared, and a gas was produced. In step nine (experiment eight), a light was added to the candle which caused the wax to melt. This showcased both a physical and chemical change because the wax melted and changed shape. But, the light and heat were formed as the candle burned. Before this lab, I was able to learn chemical and physical changes through lessons in the class and taking notes. A few terms I learned were chemical change, chemical property, physical change, physical property, extensive property, intensive property, etc. A chemical change is change in the identity and properties of matter. A chemical property is a characteristic of a substance that is observable only when the substance interacts with other substances. A physical change is a change in one or more physical properties of a substance but not in the identity of the substance. A physical property is a characteristic of a substance that can be observed without changing the identity of the substance. An extensive property is a property dependent on the amount of sample present. An intensive property is a property dependent only on a substance’s identity and not on the amount of sample present. Each of these terms that I learned from lessons helped prepare me for a basic understanding of chemical and physical changes. Ultimately, these lessons helped me with having previous knowledge in understanding this lab. In my hypothesis, I stated that: If a substance performs a physical change, then most of the substance’s original properties will stay the same because it does not become a new substance. Additionally, I said: If a substance performs a chemical change, then the substance’s original properties will change because it becomes a new substance. Thus, I believe my data supported and proved my hypothesis to be true. In each experiment, I provided whether it was a chemical or physical change and gave reasonings. In my reasonings, I stated that: If it was a chemical change, the substance’s original properties changed. If it was a physical change, the substance’s original properties didn’t completely change into a new substance. The only possible fault could be in the last experiment where a candle melting showcased both a physical and chemical change. Although this is true, it also shows that a substance can showcase both a chemical and physical change. Through this experiment, I feel that I completely understand the difference between a chemical and physical change. Previously, I was able to learn chemical and physical change through lecture and notes. Now, I was able to test it through real world experiments in order to see how this theory is applied.
