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.
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 determine the best description of what will happen when the plunger is pulled out, we can analyze the given steps of the experiment and apply our understanding of gas behavior in a closed system.
1. Remove the end cap from the tip of a 35-mL plastic syringe.
This step allows the system to be open to the surroundings.
2. Remove plunger from the syringe and insert a small marshmallow into the syringe.
By removing the plunger, the volume inside the syringe is initially increased, and the marshmallow is inserted into the syringe.
3. Place the plunger back in the syringe so the volume reading is approximately at the 15-mL mark.
By placing the plunger back in, the volume is reduced to approximately 15 mL. This creates a fixed volume within the syringe.
4. Place a syringe tip cap over the tip of the syringe.
This step seals the syringe and prevents any gas from escaping the system.
5. Pull the plunger out.
Now, this is the critical step that determines the behavior of the gas and the marshmallow. As the plunger is pulled out, the volume inside the syringe increases.
To understand the relationship between volume and pressure, we need to consider Boyle's Law. Boyle's Law states that at a constant temperature, the pressure of a gas is inversely proportional to its volume. In simpler terms, if the volume increases, the pressure decreases, and vice versa.
Based on this understanding, we can deduce that Option C ("The marshmallow expands because the volume has increased, and the pressure inside the syringe has decreased") is the best description of what will happen when the plunger is pulled out. As the volume inside the syringe increases, the pressure decreases, and as a result, the marshmallow expands.