How do I calculate the mass of a product at equilibrium given initial reactant masses and Kp?

I really don't mean to abuse this forum, but I am just stuck

**So here is the question**:

Hydrogen can be extracted from natural gas according to the following reaction:

CH

_{4}(g)+CO

_{2}(g)

2CO(g)+2H

_{2}(g)

Kp=4.5*10

^{2} at 825 K

An 85.0 L reaction container initially contains 22.3 kg of CH

_{4} and 55.4 kg of CO

_{2} at 825 K.

Assuming ideal gas behavior, calculate the mass of H

_{2} (in g) present in the reaction mixture at equilibrium.

**And here is what I did**:

| CH4 | CO2 | CO | H2 |

I | 16.35 | 14.81 | 0 | 0 |

C | -x | -x | +2x | +2x |

E | 16.35-x | 14.81-x | 2x | 2x |

(I got 16.35M and 14.81M with the moles (found with masses) and 85L)

Assume ideal behavior

Kp=Kc(RT)

^{delta n}Kc=Kp/(RT)

^{delta n}Kc=450/(0.08206*825)

^{2} =0.0982

Kc=[CO]

^{2}[H

_{2}]

^{2}/[CH

_{4}][CO

_{2}]

0.0982=(2x)

^{2}(2x)

^{2}/(16.35-x)(14.81-x)

4x

^{4}=(0.0982)(16.32-x)(14.81-x)

x=1.485M

Equilibrium concentration of H2 = 2x = 2(1.485) = 2.97M

And then I am stuck.

So I tried doing it as if it wasn't an equilibrium:

1259 mol CO2*2*2.016g H2 = 5.076 kg

But then that just doesn't make sense.

Where should I go from here? Can somebody give me a hint? Please?