How do you change the volume without changing the pressure Charles law

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Discussion Overview

The discussion centers around Charles's law, specifically exploring the relationship between volume, temperature, and pressure in gases. Participants are trying to understand how to increase volume without changing pressure while considering the implications for temperature.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant states that according to Charles's law, volume and temperature are directly proportional at constant pressure, leading to the question of how to manipulate these variables.
  • Another participant suggests that providing energy is necessary to increase temperature, but questions the meaningfulness of separating the processes of changing volume and temperature.
  • A participant expresses confusion about how to increase volume without decreasing pressure, questioning if it is possible to achieve this without altering temperature first.
  • One reply proposes methods to heat a gas, such as placing it in a hot environment or exposing it to radiation, as a way to increase temperature.
  • A participant seeks confirmation that the correct approach is to raise temperature first to subsequently increase volume, implying that starting with volume is not feasible.
  • Another participant agrees that this approach is not applicable to regular gases, indicating a limitation in the discussion.

Areas of Agreement / Disagreement

Participants generally agree that increasing temperature is the primary method to increase volume under constant pressure, but there is uncertainty about the feasibility of starting with volume to achieve this effect.

Contextual Notes

Participants express limitations in understanding the interaction between volume, temperature, and pressure, particularly in the context of maintaining constant pressure while attempting to change volume.

Who May Find This Useful

This discussion may be useful for students or individuals studying gas laws, particularly those interested in the relationships between temperature, volume, and pressure in gases.

mcfaker
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Hi,

According to Charles gas law if you keep a certain constant pressure & moles of gas, you can relate the other 2 physical quantities (Volume & Temperature) in a formula: V/T=c




If you increase T, V will increase because the temperature is directly proportional to the volume. The same happens if you decrease T, V will decrease.

Now I can't understand how to start with V instead of T. How do you increase the Volume without changing the pressure ( because it must be constant) so that the temperature increases?


Thanks in advance!
 
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You have to provide some energy to increase the temperature anyway. As both V and T change at the same time, I don't think it is meaningful to separate those processes.
 


Thanks, but the problem is how do we provide that energy? If I increase the Volume of a gas, it automatically decreases pressure(!). I don't want that to happen because the pressure must be the same if we want to explain this second gaslaw.
I cannot even imagine how it would be possible to increase volume wihout the decrease of pressure so that the temperature increases.

Is that even possible? Or am I making it way too difficult & should I just always start off with increasing temperature which will increase volume and not vice versa (This way pressure doesn't change)?
 


With the usual methods to heat a gas: Put it in a hot environment, expose it to radiation, high-energetic particles, let it do chemical or nuclear reactions or find some other way to add heat.
 


Ok So 1 more last question to make sure I am getting it :p
We start with raising the temperature which will raise volume. We do not start of increasing volume to increase temperature because that is impossible, right?
 


At least not with a regular gas, right.
 


Thanks for the answers :) It helped me a lot.
 

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