Chemical vs Physical Change Lab Essay
Purpose: To observe the difference between chemical and physical changes.
* * Hot plate * Water * Salt * Evaporating dish * Candle * Matches * Ammonium hydroxide * Watch glass * Phenolphthalein * Paper towel * Cornstarch * Iodine * Cup * Alka-Seltzer tablet * Pipet * Milk * Vinegar * Copper II sulfate * Lead II nitrate
Safety: * Goggles were worn. * Aprons were worn. * Lab station was cleaned up directly following experiments. * Hands were washed after experiments. * No eating or drinking took place in the lab. * Experiments were not conducted …show more content…
Data Analysis: 1. List all of the different signs that you observed that indicated that a chemical change had occurred. * In experiment 2, the burning wick turned from white to black. This signifies a chemical change because it was a change in color. * In experiment 3, the ammonium hydroxide changed from clear to purple when phenolphthalein was added. This signifies a chemical change because the color changed. * In experiment 5, the iodine changed from black to blue to indicant a starch. This signifies a chemical change because of the color change. * In experiment 6, the alka-seltzer, when added to water, produced bubble in water which means it was emitting gas. This signifies a chemical change because gas was produced. * In experiment 8, the lead II nitrate and copper II sulfate mixture fizzed and formed a precipitate. The fizz signifies gas and both signify a chemical change. 2. Which experiments were examples of chemical changes? * Experiments 2, 3, 5, 6, and 8 were examples of chemical changes. 3. Which experiments were examples of physical changes? * Experiments 1, 2, 4, and 7 were examples of physical changes. 4. How did you know a physical change had occurred? * The Composition of the matter did not change although a factor changed how the matter looked.
Conclusion: The lab we were asked to perform focused on the