Materials Needed:
Clamp Stand
Beaker 500ml
Distilled water
Bunsen burner
30 cm ruler
Concentrated Sulfuric acid
Glass tube
Syringe needle
Thermometer
Method:
- Heat the end of the glass tube so as to close it. The tube’s end will melt and close. Make sure the end is blocked very well.
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Using a syringe needle, inject approximately 1cm³ of Sulfuric acid into the blocked glass tube. Refer to the diagram.
- Inject the Sulfuric acid gradually, creating an air column as shown in the above diagram.
- Be careful, Sulfuric acid is a dangerous dehydrating agent that will burn your skin.
- Measure the diameter of the glass tube’s opening.
- Once this is done, set up the clamp stand and beaker as shown in the above diagram. Using the 30 cm ruler, measure the length of the air column at room temperature. Record your readings.
- Gradually, heat the water in the beaker and at certain temperatures, measure the changing length of the air column.
- Carry this out for a range of different temperature readings and record your obtained values in a table.
Data Collection:
The following table summarizes the obtained results. The temperatures are recorded in both Celsius and Kelvin Scales. The table allows us to compare how the length of air column changes with the increase in temperature.
T(K)= T(°C)+ 273.15
Data Processing and Presentation:
To analyze how the increase in temperature affects the volume of a gas, the volume must first be calculated. We do this using the above table and the following formula: V=πr²L where V=volume, π=pie=3.124, r=radius of glass tube, L=length of air column.
The radius of the glass tube is too small to measure with a normal 30 cm ruler so we assume that the radius=0.05cm
The following table represents the change in volume of the gas as the temperature is increased.
To further investigate how the increase in temperature affects the volume of a gas; a graph is drawn to show the relation between the Temperature and volume of a gas.
Conclusion and Evaluation:
From the results obtained, we can conclude that the volume of a gas does increase as the temperature is increased. By Comparing the data collected in the experiment, we can see that when the temperature was raised from 301K to 353K, the volume of the gas also increased from approximately 0.0289 cm³ to 0.032 cm³. This is evidence that the volume and temperature are directly proportional. However, the graph drawn does not greatly demonstrate the constant increase in volume. The straight line obtained is not exact and we cannot base our conclusion on this. To further investigate this property, more results must be obtained. Nevertheless, it is evident that the volume of a given amount of gas is directly proportional to the absolute temperature when the pressure is constant.
Improving the Experiment:
It would be useful to measure the radius of the glass tube using a micrometer. This would give exact values. Moreover, when the glass tube is removed from the beaker to record the air column, the temperature falls down rapidly. This causes a difficulty in recording exact results. Next time, 2 clamp stands should be used, so as to make it possible to leave the ruler next to the glass tube and not move it out of the water. The readings could be done while the glass tube stays in the water.
