Solving Unknown Quantity of Gas: Help Appreciated!

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SUMMARY

The forum discussion focuses on calculating the number of moles of gas using the Ideal Gas Law, represented by the equation PV=nRT. The specific problem involves a gas at a pressure of 1.2 atm, a volume of 31 liters, and a temperature of 87°C. Key corrections highlighted include converting volume to cubic meters and pressure to pascals to adhere to MKS units. The consensus is to use the equation PV=nRT, where n represents the number of moles.

PREREQUISITES
  • Understanding of the Ideal Gas Law (PV=nRT)
  • Knowledge of unit conversions (liters to cubic meters, atm to pascals)
  • Familiarity with thermodynamic concepts (pressure, volume, temperature)
  • Basic algebra for solving equations
NEXT STEPS
  • Learn about unit conversions in thermodynamics, specifically MKS units
  • Study the Ideal Gas Law applications in real-world scenarios
  • Explore the differences between n (moles) and N (number of molecules) in gas calculations
  • Investigate common mistakes in gas law calculations and how to avoid them
USEFUL FOR

Students studying chemistry or physics, educators teaching gas laws, and anyone interested in understanding thermodynamic principles and calculations.

chawkdee
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If anyone has time, could you please show me the working of this problem.

Greatly appreciated


b]1. Homework Statement [/b]
If I have an unknown quantity of gas at a pressure of 1.2 atm, a volume of 31 liters, and a temperature of 87C, how many moles of gas do I have?


Homework Equations



PV=nRT=NkT

The Attempt at a Solution



1.2 x 31=n8.3145 x (87+273)= N x 1.38066x10*23 x (87+273)

Can you tell me if the above numbers are correct please.
 
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chawkdee said:
If anyone has time, could you please show me the working of this problem.

Greatly appreciated


b]1. Homework Statement [/b]
If I have an unknown quantity of gas at a pressure of 1.2 atm, a volume of 31 liters, and a temperature of 87C, how many moles of gas do I have?


Homework Equations



PV=nRT=NkT

The Attempt at a Solution



1.2 x 31=n8.3145 x (87+273)= N x 1.38066x10*23 x (87+273)

Can you tell me if the above numbers are correct please.
You have to stick to MKS units. Volume has to be in m^3 not litres. Otherwise, it looks fine.

AM
 
The pressure should be in pascals as well.
 
phsopher said:
The pressure should be in pascals as well.

Of course! Thanks for catching that.

AM
 
chawkdee said:
... how many moles of gas do I have?


Homework Equations



PV=nRT=NkT

Given what is being asked, would you use nRT or NkT here?
 
Redbelly98 said:
Given what is being asked, would you use nRT or NkT here?

nRT ??
 
Why do you think that ... or is it just a random guess? The key here is: what do n and N mean?
 
Redbelly98 said:
Why do you think that ... or is it just a random guess? The key here is: what do n and N mean?

n - number of moles

N - number of molecules
 
Okay, yes. n is the number of moles, so PV=nRT is the thing to use here.

Just be careful with the units, as others said earlier.
 

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