Modeling Chemical Reactions - 2

Early in the day, Will learned about the kinds of changes in matter that can take place.He wanted to explore these changes in more depth, so he compared the two kinds of ways matter changes and how they differ. He recorded his findings in his science notebook. What are the ways in which matter changes and how do they differ?

Diego is performing an experiment using the equipment shown in the diagram. He places filings of zinc metal into a clear colorless mixture of hydrochloric acid and water and then seals the flask with a stopper as shown. He observes that the liquid in the flask bubbles and becomes hot. As time progresses, the zinc metal disappears, and the water level in the cylinder moves down as it fills with gas. Eventually, the bubbles stop forming and the flask contains a colorless liquid, while the cylinder is nearly empty of water. Diego argues that what is happening is just a physical change of the water in the flask boiling to produce water vapor, which is filling the cylinder. A classmate disagrees and hypothesizes that a chemical reaction has occurred. Provide evidence for the classmate’s hypothesis.