Students are studying the behavior of a gas in a closed system. They conducted this experiment.
1. Remove the end cap from the tip of a 35-mL plastic syringe.
2. Remove plunger from the syringe and insert a small marshmallow into the syringe.
3. Place plunger back in syringe so the volume reading is approximately at the 15-mL mark.
4. Place a syringe tip cap over the tip of the syringe.
5. Pull the plunger out.
What is the BEST description of what will happen when the plunger is pulled out?
Responses
A The marshmallow will expand because the volume inside the syringe has increased.The marshmallow will expand because the volume inside the syringe has increased.
B As the pressure increased in the syringe the volume of the syringe and the marshmallow increased.As the pressure increased in the syringe the volume of the syringe and the marshmallow increased.
C The marshmallow expands because the volume has increased and the pressure inside the syringe has decreased.The marshmallow expands because the volume has increased and the pressure inside the syringe has decreased.
D There is a direct relationship between volume and pressure so as the volume increases the pressure increases. The marshmallow shrinks.There is a direct relationship between volume and pressure so as the volume increases the pressure increases. The marshmallow shrinks.
Question 2
The best description of what will happen when the plunger is pulled out is:
C) The marshmallow expands because the volume has increased and the pressure inside the syringe has decreased.
C The marshmallow expands because the volume has increased and the pressure inside the syringe has decreased.
To understand what will happen when the plunger is pulled out, we need to analyze the steps of the experiment and the behavior of gases.
In step 1, the end cap is removed from the tip of the syringe, allowing the gas (air) inside to freely interact with the surrounding environment.
In step 2, a small marshmallow is inserted into the syringe, which occupies a certain volume within the syringe.
In step 3, the plunger is placed back in the syringe to a specific volume, approximately at the 15 mL mark. This sets the initial conditions of the gas inside the syringe.
In step 4, a syringe tip cap is placed over the tip of the syringe, preventing any air exchange between the inside of the syringe and the outside environment.
Finally, in step 5, the plunger is pulled out. When the plunger is pulled out, the volume inside the syringe increases.
Now, let's evaluate the given responses:
A) The marshmallow will expand because the volume inside the syringe has increased.
This answer is not correct. While the volume inside the syringe does increase, it does not directly cause the marshmallow to expand.
B) As the pressure increased in the syringe, the volume of the syringe and the marshmallow increased.
This answer is incorrect as well. There is no information provided that the pressure increased in the syringe.
C) The marshmallow expands because the volume has increased and the pressure inside the syringe has decreased.
This answer is the best description among the given options. As the plunger is pulled out, the volume inside the syringe increases. According to Boyle's Law, if the volume of a gas increases, the pressure decreases. As a result, the pressure on the marshmallow decreases, causing it to expand.
D) There is a direct relationship between volume and pressure, so as the volume increases, the pressure increases. The marshmallow shrinks.
This answer is incorrect. According to Boyle's Law, as the volume increases, the pressure decreases. Therefore, the marshmallow would not shrink.
So, the best description of what will happen when the plunger is pulled out is C) The marshmallow expands because the volume has increased and the pressure inside the syringe has decreased.