What is the molecular mass of the unknown gas in the atmosphere?

  • Thread starter Thread starter annalise17
  • Start date Start date
  • Tags Tags
    Mass Molecular
AI Thread Summary
To calculate the molecular mass of an unknown gas in the atmosphere, the user is working with temperature, gravitational constants, and pressure values at different altitudes. They have derived the gravitational acceleration using the formula g = GM/R^2, but are struggling to connect this with the molecular mass equation g = kT/mλ. The calculated gravitational value is significantly lower than Earth's, suggesting a smaller mass for the unknown gas. Despite rearranging the equations, the resulting molecular mass is off by a factor of 10^3 compared to known gases. Further guidance on integrating gravitational constants with molecular mass calculations is needed.
annalise17
Messages
10
Reaction score
0

Homework Statement



I need to calculate the mas of a molecule of an unknown gas in the atmosphere from the values:

T = 500 K
mass of the planet = 1.5 × 1024 kg
radius is 3.0 × 106 m
universal constant of gravitation, G = 6.67 × 10^−11 N m^2 kg^−2
P at ground level = 2.0 × 10^7 Pa
P at 50km altitude = 2.0 × 10^5 Pa

Homework Equations



g=kT/mλ

but I can't find an equation involving G :(

The Attempt at a Solution



I am completely stuck, if I can get ahint where to start I'll have a go and see if I get anywhere.
 
Physics news on Phys.org
On Earth

F = mg = GmM/R^2 so g = GM/R^2
 
Right, I've got so far as calculating g now and have calculated a very low value for g compared to Earth which is consistent with having a smaller mass than earth. I've also worked out an equation for m by rearranging λ=kT/mg ut the value doesn't match that of the two gases it could be by a factor of 10^3.
 
Last edited:
Thread 'Voltmeter readings for this circuit with switches'

Thread 'Voltmeter readings for this circuit with switches'

TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
View full post »
Thread 'Correct statement about a reservoir with an outlet pipe'

Thread 'Correct statement about a reservoir with an outlet pipe'

The answer to this question is statements (ii) and (iv) are correct. (i) This is FALSE because the speed of water in the tap is greater than speed at the water surface (ii) I don't even understand this statement. What does the "seal" part have to do with water flowing out? Won't the water still flow out through the tap until the tank is empty whether the reservoir is sealed or not? (iii) In my opinion, this statement would be correct. Increasing the gravitational potential energy of the...
View full post »

Similar threads

Molecular Specific Heat of an Ideal Gas: Computations
Replies
8
Views
2K
Ideal Gas Law and Pressure at 80°C
Replies
2
Views
3K
Finding the gas based off of mass
Replies
33
Views
2K
Determine the mass of the planet using Newton’s Law of Universal Gravitation
Replies
2
Views
3K
Changes in pressure, temp, & entropy of ideal gas in atmosphere
Replies
10
Views
2K
How Much Hydrogen Is Needed for a Balloon to Float at 10km Altitude?
Replies
22
Views
3K
What is the equation for calculating molecular flux for a gas?
Replies
4
Views
7K
How can I determine the shape of an oldie acid molecule?
Replies
1
Views
1K
Finding the Kinetic Energy using the mass, radius and initial KE
Replies
12
Views
2K
Finding the mass of a quantity of gas given P, V, T
Replies
5
Views
2K

Hot Threads

Recent Insights

Back
Top