Register to reply

Solving the ideal gas law for volume -> length

by jaded18
Tags: andgt, ideal, length, solved, solving, volume
Share this thread:
Nov13-07, 01:46 PM
P: 150
Consider an ideal gas at 27.0 degrees Celsius and 1.00 atmosphere pressure. Imagine the molecules to be uniformly spaced, with each molecule at the center of a small cube.

What is the length L of an edge of each small cube if adjacent cubes touch but don't overlap?

I know that the ideal gas law states V=nRT/p and that in this case R=8.2057(10^-5) m^3 (atm/mol*K), p=1atm, T=27+273K. What is n? Well if I calculate the volume of one mole of the gas, I get V=2.46(10^-2) m^3. And then when I use this result to find the volume of one molecule (the volume of the imaginary cube that is assumed to surround each molecule, I get V=( 1/(6.02*10^23))(8.2057)(27+273)= 4.09*10^-26 m^3

Then don't I just use this volume per molecule that I just calculated to find the length of a side of the cube by taking the cube root of it?! Why isn't the answer 0.000000003m?!

No one at the physics forum could help, so if you know how to do this prob correctly, any feedback will be awesome
Phys.Org News Partner Science news on
Experts defend operational earthquake forecasting, counter critiques
EU urged to convert TV frequencies to mobile broadband
Sierra Nevada freshwater runoff could drop 26 percent by 2100
Nov13-07, 05:41 PM
HW Helper
P: 1,539
I think you've done it properly. You get 3.44 x 10^-9 m. That's the right magnitude anyway. Maybe ask your teacher?

Register to reply

Related Discussions
Monatomic Ideal Gas volume expansion Introductory Physics Homework 9
Ideal gas law to find volume Introductory Physics Homework 4
Volume Expansivity of Ideal Gas Introductory Physics Homework 0
Ideal Gas Volume Question Introductory Physics Homework 5
Constant Volume/Ideal Gas Introductory Physics Homework 1