Part A Carbonyl fluoride COF2 is an important intermediate u
Solution
A)
 ICE Table:
 
                     [COF2]              [CO2]               [CF4]             
 initial             2.0                 0                   0                 
change -2x +1x +1x
equilibrium 2.0-2x +1x +1x
Equilibrium constant expression is
 Kc = [CO2]*[CF4]/[COF2]^2
 5.5 = (1*x)^2/(2-2*x)^2
 sqrt(5.5) = (1*x)/(2-2*x)
 2.345208 = (1*x)/(2-2*x)
 4.69042-4.69042*x = 1*x
 4.69042-5.69042*x = 0
 x = 0.82427
 
 At equilibrium:
 [COF2] = 2.0-2x = 2.0-2*0.82427 = 0.35147 M
 Answer: 0.351 M
B)
 ICE Table:
 
                     [CO]                [NH3]               [HCCONH2]         
 initial             1.0                 2.0                 0                 
change -1x -1x +1x
equilibrium 1.0-1x 2.0-1x +1x
Equilibrium constant expression is
 Kc = [HCCONH2]/[CO]*[NH3]
 0.720 = (1*x)/((1-1*x)(2-1*x))
 0.720 = (1*x)/(2-3*x + 1*x^2)
 1.44-2.16*x + 0.72*x^2 = 1*x
 1.44-3.16*x + 0.72*x^2 = 0
 This is quadratic equation (ax^2+bx+c=0)
 a = 0.72
 b = -3.16
 c = 1.44
 
 Roots can be found by
 x = {-b + sqrt(b^2-4*a*c)}/2a
 x = {-b - sqrt(b^2-4*a*c)}/2a
 
 b^2-4*a*c = 5.838
 
 roots are :
 x = 3.872 and x = 0.5165
 
 x can\'t be 3.872 as this will make the concentration negative.so,
 x = 0.5165
 
 At equilibrium:
 [HCCONH2] = x = 0.5165 M
 
 Answer: 0.5165 M


