Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Equilibrium equations

  1. Feb 13, 2006 #1


    User Avatar
    Gold Member

    Hey guys, I’m not really sure if I’m doing this right. The questions are:

    Equilibrium equations can be written directly from the balanced chemical equation. Check your textbook if you don’t know how. Then write equilibrium constant expressions for the following reactions.

    [tex] \begin{array}{l}
    a)CO_{(g)} + H_2 O_{(g)} \Leftrightarrow CO_2 _{(g)} + H_{2(g)} \\
    b)N_{2(g)} + O_{2(g)} \Leftrightarrow 2NO_{(g)} \\
    \end{array} [/tex]

    So are these the equations?

    \frac{{[CO_2 ][H_2 ]}}{{[CO][H_2 ]}} \\
    \frac{{[NO]^2 }}{{[N_2 ][O_2 ]}} \\

    It also asks me …

    In what direction, if any, would the equilibrium be shifted if the following changes were done to the above reactions

    1) CO2 is added to reaction 1
    2) Nitrogen gas is removed from reaction 2

    I don’t really understand the 2nd part. How do I determine what to do?
  2. jcsd
  3. Feb 13, 2006 #2
    Yes those expressions in the first part are correct.

    This is Le Chatelier's Principle, which basically says that if a system at equilibrium changes, then the system will shift to undoe that change. Therefore, if you add something to one side, it will shift to the other side. What do you think will happen if you remove something?
  4. Feb 13, 2006 #3


    User Avatar
    Gold Member

    If you remove a reactant, won't hte products also reduce?
  5. Feb 13, 2006 #4
    Look in your chem book. Its in there. What direction will it go to maintain equilibrium? Hint, Le Chatelier
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook