Finding Equilibrium pressure and final mass of a solid in a gas equation, comprehensive help?

Question

anonymous · Answer

In the following equation:

$$I_{2}(l) + H_{2}(g) \leftarrow \rightarrow 2HI(g)$$

Given:
Temperature = 25 celcius = 25+273 = 298 Kelvins
Kc = 200

anonymous · Answer

So I found this later:
Kp = 4893
The starting pressure = 5.00 atm
Volume = 2.00 L

Starting moles of I2 = twice of H2
(I found the mass of I2 starting to be 208g)

SO my problem is, how do I find the 
1. Equilibrium Pressures
and more pressingly
2. Final mass of I2 at equillibrium.

anonymous · Answer

Here's my take. Since I already found Kp, it is equal to P of products / P of Reactants. since only 1 on both sides... I already found the initial P of it, which is 5.00.
The change of the ICE box is|dw:1394586882524:dw|
so...
4893 = 4x^2/5-x
Getting the quadratic
$$4x^{2} + 4893x - 24463$$
Which I found x = 4.97
Final pressure:
5 -4.97 = 0.03 H2
2x4.97 = 9.94 HI