Year 12: Cambridge Physics Problem (Gas and Pressure)

In summary, the conversation was about a constant-volume gas thermometer filled with an ideal gas and connected to a manometer with a dead space of volume V/4. The person was asking for help in finding the sensitivity of the thermometer and sketching its variation with temperature. They also requested for a diagram with all the information labeled, as they were having trouble visualizing the apparatus.
  • #1
johnconnor
62
0
Guys I'm weak in heat and kinetic theory, so I'm going to need extra guide and pointers from you guys to solve this and the coming questions. Thank you.

Question:
The bulb of a constant-volume gas thermometer has a volume V and is connected by a long narrow capillary tube to a manometer, where there is a dead space of volume V/4 above the liquid. The thermometer is filled with an ideal gas at pressure p0 and temperature T0.

(i) Find an expression for the sensitivity of the thermometer (rate of change of pressure with temperature) at temperature T if the manomenter remains at temperature T0.

(ii) Sketch the variation of sensitivity with temperature for the range T/K = 0 to ∞.

(iii) Show, on the same axes, sensitivity as a function of temperature for the same bulb connected to a manometer with a dead space of negligible volume (a) when filled to give the same value of p0 at T0, and (b) when filled with the same mass of gas as previously.

Attempt:

(i) This is the diagram of the apparatus which I think is like. Is it correct?
DSC02993.jpg

Or is it this one?
C638A50B86140A65A0528F55C9F4C1C728D7B13A_large.jpg
 
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  • #2
It is the second diagram. The volume is kept constant by adjusting the Height of the mercury reservoir and the temperature is determined by measuring the pressure(h)
 
  • #3
truesearch said:
It is the second diagram. The volume is kept constant by adjusting the Height of the mercury reservoir and the temperature is determined by measuring the pressure(h)

Where exactly is the dead space V/4, then? Would you mind showing me a diagram with all the information labelled? Sorry for not being able to even imagine the apparatus properly. Thanks in advance!
 
  • #4
Can anyone please help me with starting the question? Thank you very much in advance.
 
  • #5


As a scientist, it is important to understand the concepts and principles behind the problem rather than just relying on diagrams. Can you provide more information on the problem, such as the specific equations and variables involved? This will help in providing a more accurate response to your question. Additionally, I would suggest seeking guidance from your teacher or a tutor to improve your understanding of heat and kinetic theory, as they are fundamental concepts in physics.
 

1. What is the relationship between gas pressure and temperature?

The relationship between gas pressure and temperature is described by the ideal gas law, which states that the pressure of a gas is directly proportional to its temperature, given a constant volume and number of moles. This means that as the temperature of a gas increases, its pressure will also increase, and vice versa.

2. How does the number of moles of gas affect pressure?

The number of moles of gas present in a given volume also has a direct impact on the gas pressure. According to the ideal gas law, as the number of moles increases, the pressure will also increase, given a constant temperature and volume. This means that if the number of moles is doubled, the pressure will also double.

3. What is the difference between absolute and gauge pressure?

Absolute pressure is the total pressure of a gas, including atmospheric pressure, while gauge pressure is the difference between the absolute pressure and atmospheric pressure. In other words, gauge pressure only measures the pressure above atmospheric pressure, while absolute pressure takes into account the pressure of the atmosphere itself.

4. How does the volume of a gas affect its pressure?

According to Boyle's Law, the volume of a gas is inversely proportional to its pressure, given a constant temperature and number of moles. This means that as the volume of a gas decreases, its pressure will increase, and vice versa. This relationship is known as the inverse relationship between volume and pressure.

5. How do changes in altitude affect gas pressure?

As altitude increases, the atmospheric pressure decreases due to the decrease in the weight of the air above. This decrease in atmospheric pressure also affects the pressure of gases within a closed system, as the atmospheric pressure is no longer equalized with the pressure of the gas. This is why, for example, a balloon will expand as it rises to higher altitudes where the atmospheric pressure is lower.

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