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**confused20** I was having difficulty with the following problem. Can someone please tell me if it is correct?

Ethanol can be synthesized by the reaction of ethylene with water vapor. K = 3.4 x 102

C2H4 (g) + H2O (g) ⇌ C2H5OH (g)

If you start with 5.4 atm of ethylene and 5.4 atm of water vapor, what are the concentrations of each of the gases at equilibrium?

i 5.4 5.4 0 K = x = 3.4 x 102

c –x –x +x (5.4–x)2

e 5.4–x 5.4–x x x = (3.4 x 102)(29–10.8x+ x2)

x = 9.9 x 103–3.7 x 103 x+3.4 x 102 x2

3.4 x 102 x2– 3.7 x 103 x+9.9 x 103 = 0

Is it right that at this point I would use the quadratic formula where a= 3.4 x 10^2, b= -3.7 x 10^3, c=9.9 x 10^3? It says the answer is 4.0 but I get 4.7. What did I do wrong? Any input would be greatly appreciated.