Students Study Changes in Chemistry

Sophomores in Gigi Mathews’ Chemistry 1 course strapped on their safety goggles, turned on the Bunsen burners and organized their test tubes for a special lab studying physical and chemical changes.

As Mathews previously taught her students, “Chemistry is the study of matter and the changes it undergoes. These changes can be broken down into two classes—physical and chemical. In a physical change, one or more physical properties of a substance are altered. Examples include size, shape, color and physical state/state of matter. A chemical change results in the formation of one or more ‘new’ substances. These new substances differ in chemical properties and composition from the original substance. The rusting of iron and the burning of paper are two examples of chemical change.” She explained that this lab was “to understand the difference between physical and chemical change and to recognize each type of change when it occurs.”

However, before experimenting, sophomores had to answer a number of Mathews’ pre-lab questions to ensure they had a good grasp on safety measures and proper handling of the materials—namely, powdered sulfur, sodium chloride, hydrochloric acid, strips of paper, iron filings, magnesium ribbons, silver nitrate and copper sulfate pentahydrate.

With this grounding of information and safety practices, sophomores got to work at 16 stations. At each of these stations, students would test the reaction of different materials to different stimuli at every step and make detailed qualitative and quantitative observations, remarking on and testing for any physical or chemical property changes.

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