Apply. Let’s apply what you know in a simple experiment. A student fills a bottle with ½ cup of vinegar. Next, the student adds 2 teaspoons of baking soda in a balloon. Carefully, the student attaches the balloon to the top of the bottle being careful not to mix the vinegar and baking soda. The initial mass of the vinegar bottle and filled balloon is 239.1 grams.

Question

Mass = 239.1 grams

Mass = 237.2 grams


The student lifts the balloon causing the baking soda to combine with the vinegar in the bottle. The student observes the vinegar start to bubble and fill the bottle. The balloon also begins to expand filling with gas. The student records a new mass of 237.2 grams.

4. What reaction did the student observe when the baking soda and vinegar mixed?

When the student mixed the baking soda with the vinegar, they saw a reaction where it bubbled and fizzed up, filling the balloon with gas. The fizzing happened because they produced carbon dioxide gas, which made all those bubbles!

5. Did the mass increase or decrease? Explain what happened to cause a change in mass.

The mass went down from 239.1 grams to 237.2 grams, so it decreased. This happened because when the baking soda and vinegar reacted, they created carbon dioxide gas that escaped into the air. Since the gas left the bottle, the total weight got a little lighter.

6. Did a physical or chemical change occur? Explain.

A chemical change happened in this experiment. This is because the baking soda and vinegar mixed together and changed into new things, one of which was carbon dioxide gas. The bubbling and fizzing are signs that something new was made, and you can't just put the baking soda and vinegar back together to get what you started with. That’s why it’s a chemical change!
am I right?

Answer 1

Yes, you're absolutely right! Let's summarize your answers:

4. Reaction Observed: When the baking soda (sodium bicarbonate) mixed with the vinegar (acetic acid), a chemical reaction occurred that produced bubbles of carbon dioxide gas. This gas caused the fizzing and made the balloon expand as it filled with gas.

5. Change in Mass: The mass decreased from 239.1 grams to 237.2 grams. This decrease in mass occurred because the reaction produced carbon dioxide gas, which escaped into the air. Since the gas was not trapped within the system (the bottle and balloon), it contributed to a loss of mass.

6. Type of Change: A chemical change occurred during this experiment. The mixing of baking soda and vinegar led to the formation of new substances, including carbon dioxide gas and water. The observable fizzing and bubbling were indicators of this chemical reaction. Additionally, because you can't simply revert the products back to the original reactants, it confirms that a chemical change took place.

Great job with your experiment and analysis!