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The table shows data obtained when a hydrogen peroxide solution decomposed to form water and oxygen in the presence of a catalyst - Leaving Cert Chemistry - Question a - 2008
Question a
The table shows data obtained when a hydrogen peroxide solution decomposed to form water and oxygen in the presence of a catalyst. Time (seconds) 0 10 20 30 40 50 6... show full transcript
Worked Solution & Example Answer:The table shows data obtained when a hydrogen peroxide solution decomposed to form water and oxygen in the presence of a catalyst - Leaving Cert Chemistry - Question a - 2008
Step 1
On graph paper, plot the volume of oxygen produced (y-axis) against time (x-axis).
Answer
To plot the graph:
- Set up your axes with the x-axis representing time (seconds) ranging from 0 to 70, and the y-axis representing the volume of oxygen gas produced (cm³) ranging from 0 to 100.
- Mark the points from the data table onto the graph:
- (0, 0)
- (10, 30)
- (20, 53)
- (30, 79)
- (40, 85)
- (50, 88)
- (60, 88)
- (70, 88)
- Connect the points with a smooth curve to show the relationship clearly.
Step 2
Find from the graph the volume of oxygen produced in the first 15 seconds.
Answer
By observing the graph at 15 seconds:
- Draw a vertical line from the 15-second mark on the x-axis upwards until it intersects with the curve.
- Estimate where the intersection meets the y-axis. It should be around 40 cm³. Thus, the volume of oxygen produced in the first 15 seconds is approximately 41 to 44 cm³.
Step 3
Use the graph to find the time at which the reaction was finished.
Answer
The reaction is considered finished when the volume of oxygen produced levels off. From the graph:
- The volume reaches a maximum of about 88 cm³ and remains constant.
- This happens around 57 to 60 seconds. Therefore, the reaction was finished at approximately 57 to 60 seconds.