[Star]

I've had enuff >.<    this dam question i cant seem to figure it out and ive tried every different thing i can think of soo far so if anyone else here can show me how to work it out itd b much appreciated :}

at 25 degrees C,   Kc = 0.145 for the reaction in the solvent CCl₄:  2BrCl  Br₂ + Cl₂    IF the initial concentrations of each substance in a solution are 0.0400M - determine the equilibrium concentrations of each substance

[Borek]

Show you work so far.

[Gargamel]

Try this
                2BrCl              Br₂      +        Cl₂
Start          0,04M                 0,04M           0,04M
End            0,04M-2x             0,04M+x       0,04M+x

Every time we use 2 mole of BrCl we get 1 mole of Br and 1 mole of Cl and vice versa.

Find x by using the equilibrum law, and I think you can figure out the rest.

[Star]

ok wat i did was work out that Qc was = 1.0  therefore Qc>Kc  (1.0>0.145) sooo   >.<  i thought it meant i use up products therefore BrCl:   0.0400 + 2x ?  and Cl2 = 0.04 - x ? no?
in any case i ended up with    Kc = (0.4 -x)^2/(0.04 + 2x)^2  = 0.145      (im gonna take another stab at it now  >.< )

[Gargamel]

Oh I'm so sorry if I confused you. You got it right! (forgot the stoichometric coefficient before BrCl so my Q was 0,04. But it is 1 as you say).

Just find x in your equation and insert in

[BrCl] = 0,04 + 2x
[Br₂] = [Cl₂] = 0,04 - x

Hope this help