Question

If a reaction vessel initially contains only CO and NH3 at concentrations of 1.00 M and 2.00 M, respectively, what will the concentration of HCONH2 be at equilibrium? Kc=0.880

Answer 1

If a reaction vessel initially contains only CO and NH3 at concentrations of 1.00 M and 2.00 M, respectively, what will the concentration of HCONH2 be at equilibrium? Kc=0.880

CO + NH3 = HCONH2

this is already balanced

Kc = [HCONH2 ] /([CO][NH3])

initially

[HCONH2 ] = 0

[CO] = 1

[NH3] = 2

in equilbirium

[HCONH2 ] = 0 + x

[CO] = 1 - x

[NH3] = 2 - x

substitute in K

K = 0.88

0.88 = (0 + x) /((1-x)(2-x))

0.88 (2 -3x + x ^2) = x

2 -3x + x ^2 = 1.136x

x^2 - (4.136)x +2 = 0

x = 0.5591

[HCONH2 ] = 0 + x = 0.5591

[CO] = 1 - x = 1-0.5591 = 0.4409

[NH3] = 2 - x = 1.4409

[HCONH2 ] = 0 + x = 0.5591