Kinetic Theory of Gases- no. of collisions

AI Thread Summary
To calculate the number of collisions per second of oxygen molecules with a 1 m² area of the vessel wall, the root mean square speed (Vrms) is essential, derived from the equation Vrms = √(3RT/M). The pressure can be expressed using the formula P = ⅓ (mN/V)(Vrms)², where m is the mass of one molecule, N is the total number of molecules, and V is the volume. The discussion emphasizes the importance of not assuming a specific shape for the vessel, suggesting a more general approach by considering a volume V instead of a cube. The calculation of collisions involves determining the total number of collisions and dividing by six for one face of the vessel. Understanding these principles is crucial for solving the problem accurately.
erisedk
Messages
372
Reaction score
7

Homework Statement


One mole of oxygen at 27°C and at one atmospheric pressure is enclosed in a vessel.
Assuming the molecules to be moving with Vrms, find the number of collisions per second which the molecules make with 1 m2 area of the vessel wall.

Homework Equations


vrms = √(3RT/M)
PV = nRT

The Attempt at a Solution


I want to find the total number of collisions that the molecules make with a cube of side 1m and divide that by 6 to get the no. of collisions with one face.
I know how to calculate pressure (using momentum etc), which gives the equation P = ⅓ ( mN/V ) (vrms)2 where m is the mass of one molecule, N total no. of molecules, V volume.
I don't know how to combine all this information.
 
Physics news on Phys.org
You combine it ONE step at a time. Your first error: you assume a 1 meter cube. Why?
 
Okay I won't. I'll assume a volume V. What next?
 
Also, do I need to even assume that it's a cube? How about I just assume a randomly shaped vessel with volume V?
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Pressure of Gas Exerted on Wall
Replies
4
Views
4K
I Why pressure stays the same when doubling both volume and temperature?
Replies
35
Views
4K
B Collision time interval of a gas molecule with wall of container
Replies
6
Views
2K
Kinetic energy and momentum in an elastic collision
Replies
22
Views
3K
Question about the relation b/w mean free path and other variables
Replies
2
Views
2K
Kinetic Theory and Elastic Collisions
Replies
5
Views
7K
Finding recoil velocity of an object during a collision
Replies
9
Views
2K
Velocity after collision and Kinetic Energy.
Replies
11
Views
2K
Basic Kinetic theory: How many molecules are there?
Replies
3
Views
2K
Explaining Brownian Motion & Gas Laws: Homework Solutions in 65 chars or less
Replies
3
Views
2K

Hot Threads

Recent Insights

Back
Top