[djdato]

hey guys...drawing a blank here...

2HI(g) <----> H₂(g) + I₂(g)

mixture was prepared by placing 4.0 mol of HI in a 2.0 L vessel at 330 C. At Equilibrium 0.44 mol of H₂ and 0.44 mol of I₂ were present. Calculate the value of the equilibrium constant at this temperature.

Could someone point me in the right direction?
grateful for help...thnx   

[xiankai]

write out the K_c expression for the reaction, then plug in the values.

[Rich2189]

K_c = [H₂][I₂]
         [HI]²

Also since it is an all gas  equation you can also use K_p Where p is pressure/ partial pressure.

K_p = p(H₂) p(I₂)
          p(HI)²

[Yggdrasil]

mixture was prepared by placing 4.0 mol of HI in a 2.0 L vessel at 330 C. At Equilibrium 0.44 mol of H₂ and 0.44 mol of I₂ were present.

If 0.44 mol of H₂ and 0.44 mol of I₂ are present at equilibrium, how much HI would remain unreacted?

[djdato]

hey guys. Thanks for the help. I've found the answer to be K = 0.02. Is this right?

[Rich2189]

Yes that's what I got.

4 - (0.44 X2) = 3.12


(0.44x0.44) divided by 3.12²

= 0.01988888

= 0.02 to 1 s.f

And as a note there are no units for this particular equilibrium constant.