Photo AI
In an experiment to verify Boyle's law, a student measured the volume $V$ of a fixed mass of gas at different values of the pressure $p$ - Leaving Cert Physics - Question 1 - 2015
Question 1
In an experiment to verify Boyle's law, a student measured the volume $V$ of a fixed mass of gas at different values of the pressure $p$. The temperature of the gas ... show full transcript
Worked Solution & Example Answer:In an experiment to verify Boyle's law, a student measured the volume $V$ of a fixed mass of gas at different values of the pressure $p$ - Leaving Cert Physics - Question 1 - 2015
Step 1
Describe, with the aid of a labelled diagram, how the student obtained the data.
Answer
To measure the relationship between the volume and pressure of a gas, the student used a sealed syringe connected to a pressure gauge.
Diagram Components:
- Volume Scale: The syringe has a scale to measure the volume of the gas.
- Pressure Gauge: A gauge measures the pressure of the gas inside the syringe.
- Method of Changing Volume/Pressure: By pushing or pulling the plunger of the syringe, the volume of the gas is altered, which in turn changes the pressure, recorded on the gauge.
Procedure:
- The gas volume was adjusted by moving the plunger to specific markings on the volume scale.
- The pressure for each volume was read from the pressure gauge, with multiple readings taken to ensure accuracy.
Step 2
Draw a suitable graph to show the relationship between the pressure of the gas and its volume.
Answer
The graph should be plotted with pressure () on the y-axis and volume () on the x-axis. The points to plot would be:
- (80, 324)
- (120, 214)
- (160, 165)
- (200, 135)
- (240, 112)
- (280, 100)
Graphing Steps:
- Label the Axes: Y-axis as 'Pressure (kPa)' and X-axis as 'Volume (cm³)'.
- Plot Points: Mark the points derived from the data.
- Draw a Straight Line: Use a ruler to connect the points, showing that the graph curves downwards, indicating an inverse relationship.
Step 3
Explain how the graph verifies Boyle's law.
Answer
Boyle's law states that for a given mass of gas at constant temperature, the pressure of the gas is inversely proportional to its volume. This is represented mathematically as:
From the graph, as the volume () increases, the pressure () decreases, illustrating this inverse relationship. The straight line on a graph of versus reflects this direct proportionality, confirming that Boyle's law holds for the measured data.
Step 4
Use your graph to estimate the pressure of the gas at a volume of 250 cm³.
Answer
By locating 250 cm³ on the x-axis of the graph and drawing a vertical line upward, intersect with the curve to find the corresponding pressure on the y-axis. This gives an estimated pressure of approximately 108 kPa.
Step 5
Why might the temperature of the gas have changed significantly during the experiment?
Answer
The temperature of the gas may have changed due to rapid compression or expansion. This process can cause the gas to either absorb heat from the surroundings or lose heat to the environment, leading to significant temperature fluctuations.
Step 6
How did the student ensure that the temperature of the gas was the same for each measurement?
Answer
The student ensured that the temperature remained constant by conducting the experiment slowly, allowing the gas to equilibrate with the surrounding temperature between measurements. Additionally, they could have utilized a water bath to maintain a stable temperature throughout the experiment.