[sijuki]

Hi all,
So I've got this question on my assignment asking me to explain what the physical and chemical characteristics of a "gas" equilibrium whilst explaining the forward/reverse reactions and their dynamic nature.

My problem, what is a "gas" equilibrium? Is it the same as a normal equilibrium? I'm also not sure what characteristics are, is it when the forward reaction is equal to the reverse reaction?

Also on another question, it asks to explain how the equilibrium constant is calculated and I'm fine with that, but its sorta bugging me how they came up with the equation. where K=[products]/[reactants]
Can anyone explain it to me in not so difficult terms?

[juanrga]

A gas equilibrium is a "normal equilibrium" as

aA + bB  cC + dD

where A, B, C, and D are gaseous species. From this you would be able to ask the questions from the definition and properties of an equilibrium.

[ramboacid]

Also on another question, it asks to explain how the equilibrium constant is calculated and I'm fine with that, but its sorta bugging me how they came up with the equation. where K=[products]/[reactants]
Can anyone explain it to me in not so difficult terms?

The equilibrium constant is just the ratio between the rate constant of the forward reaction (k_f) and the rate constant of the reverse reaction (k_r). As equilibrium is reached when the rate of the forward reaction is the same as the rate of the reverse reaction, the equilibrium constant can be found by setting the rates of the forward and reverse reactions as equal:
k_f[reactants] = k_r[products]
And then solving:
k_f/k_r = [products]/[reactants]
K_eq = [products]/[reactants]

A more in depth explanation can be found by looking up the Law of Mass Action, though it is probably a bit more involved than necessary for your problem.