Answer:
See explanation below
Explanation:
Let's write the equilibrium reaction:
CO(g) + NH3(g) <------> HCONH2(g) Kc = 0.9
We know the initial concentrations which are 1 and 2 M. In order to know the concentration of equilibrium, we need to do an ICE chart, and then, write the equilibrium expression for this reaction to calculate the concentration.
The ICE chart:
CO(g) + NH3(g) <------> HCONH2(g) Kc = 0.9
i) 1 2 0
c) -x -x x
e) 1-x 2-x x
The equilibrium expression:
Kc = [HCONH2] / [CO][NH3]
Replacing the values we have:
0.9 = x / (1-x)(2-x)
0.9(1-x)(2-x) = x
0.9(x²-3x+2) = x
0.9x² - 2.7x + 1.8 = x
0.9x² - 3.7x + 1.8 = 0
From here, we solve for x using the general formula for a quadratic expression:
x = -b ±√b² - 4ac / 2a
Replacing the values here:
x = 3.7 ±√(3.7)² - 4 * 0.9 * 1.8 / 2*0.9
x = 3.7 ±√13.69 - 6.48 / 1.8
x = 3.7 ± 2.69 / 1.8
x1 = 3.7 - 2.69 / 1.8 = 0.56
x2 = 3.7 + 2.69 / 1.8 = 3.55
As 3.55 is > 1 and 2 from the initial concentrations, the correct value is x1 therefore:
[HCONH2] = 0.56 M
