1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Physical chemistry problem

  1. Nov 11, 2007 #1
    1. The problem statement, all variables and given/known data
    In a closed system shown in the Figure below (http://i18.tinypic.com/7x1r8mo.jpg), the piston is freely moving without friction and the system is initially filled with gaseous molecules A only. The mass of a piston is 100 g, its area is 10 cm2 and it is 10 cm from the bottom in the initial state of equilibrium. The pressure outside the system is 1 atm; temperature inside the system is 900 ºC.

    a) Calculate the initial number of molecules in the system;
    b) Write the equation describing the initial rate of decrease in the number of gaseous
    molecules if it is known that molecules A stick to the surface of the piston upon
    collision with it (molecules do not stick to any other surfaces; the processes when
    gaseous molecules react with a hot substrate surface are the basis of the chemical
    vapour deposition technology). Obtain numerical value of the initial rate.

    2. Relevant equations

    3. The attempt at a solution

    I'm really struggling with where to start on this. I'v been handed a large physical chemistry book and basically been left to my own devices. I understand the problem relates to molecular theory of gasses but could you please steer me in the right direction.
  2. jcsd
  3. Nov 12, 2007 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    You can start by determining the pressure exerted by the piston on the confined "Molecules A, 900 C". The external pressure is 1 atm but the piston has mass as well.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Physical chemistry problem
  1. Physical Chemistry (Replies: 0)