Question

kenya finds instructions for a demonstration on gas laws.

1. place a small marshmallow in a large plastic syringe
2. cap the syringe tightly
3. pull the plunger back to double the volume of gas in the syringe

which best describes the purpose and outcome of the demonstration?
○ this is a demonstration of charles’s law. as the volume increases, the temperature decreases, and the marshmallow will freeze.
○ this is a demonstration of charles’s law. as the volume increases, the temperature increases, and the marshmallow will melt.
○ this is a demonstration of boyle’s law. as the volume increases, the pressure decreases, and the marshmallow will grow larger.
○ this is a demonstration of boyle’s law. as the volume increases, the pressure increases, and the marshmallow will shrink.

Explanation:

1. Recall gas laws: Boyle’s law relates pressure and volume (constant temp), Charles’s law relates volume and temperature (constant pressure).
2. The experiment involves changing volume (pulling plunger) and observing marshmallow (gas inside marshmallow).
3. Boyle’s law: \( P_1V_1 = P_2V_2 \) (inverse relationship between \( P \) and \( V \) at constant \( T \)). Pulling plunger increases volume of gas in syringe, so pressure decreases. Marshmallow has trapped gas; lower pressure allows its gas to expand, so marshmallow grows.
4. Eliminate Charles’s law options (they involve temperature, experiment doesn’t mention temp change). Eliminate the wrong Boyle’s law option (pressure doesn’t increase with volume). The correct option is the one about Boyle’s law, volume increase → pressure decrease → marshmallow grows.

Answer:

This is a demonstration of Boyle’s law. As the volume increases, the pressure decreases, and the marshmallow will grow larger. (The option with this description)