college chemistry
posted by sparkle .
please help!
If the initial pressure of I2(g) is 1.738 atm, calculate the % decomposition of I2(g) when the reaction comes to equilibrium according to the balanced equation. The value of Kp at 1000 K is 0.254. The initial pressure of the reaction products is 0 atm.
I2(g) = 2I(g)

Set up an ICE chart, substitute into Kp expression, and solve.

i did.. it was wrong for the last time

for the last time i did it*

If you post what you did perhaps I can find the error.

initial:
I2 = 1.738 atm
2I = 0
change:
I2 = 2x
2I = x
equilibrium:
I2 = 1.738  2x
2I = x
so i set the equation as
0.254 = x/(1.738  2x)
and i solved for x. i got 0.292
and after that how do i get % decomposition? 
equilibrium:
I^ (not 2I) = 2x
I2 = 1.738x
Then Kp = pI^^2/pI2
0.254 = (2x)^2/(1.738x).
Solve for x. You didn't have 2x and then didn't square it.
%decomposition = (pI^/1.738)*100 = ?? 
What is the pressure in a 10.0 cylinder filled with 0.405 of nitrogen gas at a temperature of 327k?