Questions
- Form the graph that has been made by the result of the experiment, the relationship between temperature and height (which is same as height in this experiment) was directly proportional.
- The Charles’ law defined that the relationship between temperature and the volume for a gas at constant pressure is linear or V=k (constant)T. Every gas we use gives the same value of temperature for this intercept, -273℃ and the behaviour of gases tells us that the temperature has an absolute zero. So if I want to double the volume at constant pressure of a gas initially at 10℃, I heat it to 293℃ not 20℃.
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A) Effect of changing the pressure at constant temperature: From the Kinetic Molecular Theory, temperature (heat) is the kinetic energy in an atom. Therefore the more kinetic energy molecules have, the higher temperature is. If the kinetic energy is constant which mean the temperature is at constant, only volume can decrease or increase the level of pressure. If I want to increase the pressure which means I want molecules hit each other more frequently, then volume will decrease so that the space that atoms have will be less so molecules will hit each other more frequently. On the other hand, if the pressure decreases, volume will increase according to the Boyles’ law that volume and pressure are inversely proportional.
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B) Effect of changing the temperature at constant pressure: At constant pressure, the temperature will either increase or decrease. So, volume will change depends on how the temperature will change. This phenomenon was proved by Charles who said the temperature and the volume are directly related. For example, if the temperature increases, the volume will increase. If temperature decreases, the volume will decrease and vice versa. This could happen due to the speed of molecules. If temperature is high, kinetic energy will increase then the seed of molecules will increase too which means the space (volume) will be bigger due to molecules’ collision. On contrast, if temperature is low, kinetic energy will decrease then the speed of molecules will decrease too which means their power of collision will slow down so volume will decrease. This is shown prominently for gas because molecules in gas are more freely moveable.
Conclusion
From the experiment, I was able to find out the relationship between the temperature and the height (I used height instead of using volume because these are same) that the temperature and the height were directly related. To find the height, I had to subtract the scale of the end of capillary from the scale of the bottom of bubble. And, for the temperature, all I had to do was just read the scale of thermometer per 10℃. And then I need to change the Celsius into the Kelvin temperature because, the Lord Kelvin said that a reasonable temperature scale should start at a true zero value. Therefore, according to the results, when the temperature increased, the height (volume) increased too. However, the constancy keeps increasing in the results which must be similar to each other’s. . According to the Charles’ law, the temperature and the volume (height) are directly proportional. Therefore, the height (volume)*inversed temperature showed constancy. Moreover, there was not vast difference between temperatures. It was because of the substance of molecules that we used liquid. The characteristics of liquid are definite volume, take the shape its container and incompressible. Moreover, the motion of molecules in liquid is less random than that of gas. Therefore, there was not significant reduction.
Absolute zero is the coldest temperature that the atoms can be which is -273℃. When the atoms are all stopped the gas is absolutely as cold as can be so we call this phenomenon as absolute zero. When the temperature is -273℃, the volume will be 0. However, gases do not really reach a 0 volume but the spaces between molecules approach 0. We use the unit called Kelvin (K) because absolute zero means the temperature never goes down more than -273℃ so we make the temperature as positive value to calculate easier.
Limitation
There were few limitations in my experiment. The height difference between at 82℃ (right after boiling the water) and at 24℃ (room temperature) was quite strange. According to the theory, at 82℃, the height (volume) must be the greatest but in the experiment, the height showed the lowest scale. Moreover, it does not show a graphically straight line which means there was something wrong with the temperature. I think that was because of the room temperature or the problem in cooling process. When we cool the water, we used ice for saving time otherwise it will take hours till the room temperature. Besides, we are not sure that the temperature will be constant in the room. Then the speed of cooling time will be different and there might be error in calculating the volume which is height in this experiment. There were huge uncertainties which were affected by the ruler I think. The ruler did not have more detailed scale like electronic rulers. Though we can see the gap between the smallest unit but we can write it down because we do not know exactly what it is.
Improvement
To improve the experiment, we may do more trials to make the experiment more accurate. Also, make it sure that our experiment will be done under the exactly same circumstance. So that there will not be any mistake in temperature and proportion with volume. Sometimes, we missed to measure the height at proper temperature so we assumed the approximate height. For the next time, make it sure that we must be always ready for taking the scale of height at right temperature. At some temperature, the bubble thingy did not move at all. For example, at 72℃ and 62℃, there was not any difference in height. That might be because of inappropriate working problem. We have to make it sure that the equipment works properly. Besides, preparing more accurate ruler may help to reduce uncertainties.
