Confused - Pressure in a canister?

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Discussion Overview

The discussion revolves around the calculation of pressure in a CO2 canister, specifically addressing the discrepancy between a calculated pressure of 444 Bar using the ideal gas law and a manufacturer-quoted pressure of 60 Bar. The scope includes theoretical calculations and considerations of gas behavior under pressure.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • A participant calculates the pressure in a CO2 canister using the ideal gas law and arrives at 444 Bar, questioning the manufacturer's quoted pressure of 60 Bar.
  • Another participant suggests that the volume should be converted to cubic meters, although the original poster claims to have already done this in their calculation.
  • A participant proposes that CO2 may not behave as an ideal gas, implying that a different formula might be necessary for accurate pressure calculation.
  • Some participants express confusion about the source of the manufacturer's pressure quote, suggesting that the pressure could relate to the vapor pressure of CO2 at room temperature.
  • There is a suggestion that the ideal gas assumption may not apply, leading to the need for alternative equations to describe the gas behavior.
  • A link to a phase diagram for carbon dioxide is provided, possibly to illustrate the relationship between pressure and temperature for CO2.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the reason for the discrepancy between the calculated and quoted pressures. Multiple competing views regarding the behavior of CO2 and the applicability of the ideal gas law remain unresolved.

Contextual Notes

The discussion highlights potential limitations in the assumptions made about gas behavior, the definitions of ideal versus non-ideal gases, and the relevance of vapor pressure in the context of the canister's contents.

b.kiddo44
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A manufacturer quotes a standard CO2 canister contains 16g of CO2 at a volume of 20cm^3.

So I need to calculate the pressure in the canister...

Using ideal gas law

P = nRT/V
n = 0.364mol (16 of co2)
R = 8.314 J/Kmol (universal gas constant)
T = 294k (gas is at room temp 21 deg C)
V = 20cm3 (volume of canister as quoted)

P = 444 Bar

However the manufacturer quotes the canister pressure to be 60Bar! This seems a bit more realistic to me but I've no idea how this could be the case.

Any thoughts to clear up the confusion?
 
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Its must be cubic meter.Convert 20 cm3 to meter3
 
Good point, but I already did the conversion to m^3 in the calculation to give 444Bar.
 
I don't know chemical very well but maybe there's another formula to calculate pressure.Maybe CO2 supposed to be non-idel gas.
Your equation seems correct.
 
hum, I don't think it matters if the gas is 'ideal' or not. The manufacturer quoting 16g of CO2 in a 20cm^3 canister stored at room temperature. I'm confused as to where the 60 Bar quote comes from.
 
Perhaps the CO2 is not all a gas under pressure and the pressure is the vapor pressure at a given temperature.
 
You wrote it isn't it ?
 
there's only two option.First option this is not an idel gas.Ideal gas make the equation simpler but maybe there's another type of equation which I said before.
Second think As you said its not 60 bar

there's no other option cause our solution is correct.
 

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