Answer:
[N2] = 0.3633M
[H2] = 1.090M
[NH3] = 0.2734M
Step-by-step explanation:
Based on the reaction of the problem, Kc is defined as:
Kc = 0.159 = [NH3]² / [N2] [H2]³
Where [] are the equilibrium concentrations.
The initial concentrations of the reactants is:
N2 = 1.00mol / 2.00L = 0.500M
H2 = 3.00mol / 2.00L = 1.50M
When the equilibrium is reached, the concentrations are:
[N2] = 0.500M - X
[H2] = 1.50M - 3X
[NH3] = 2X
Where X is reaction quotient
Replacing in the Kc equation:
0.159 = [2X]² / [0.500 - X] [1.50 - 3X]³
0.159 = 4X² / 1.6875 - 13.5 X + 40.5 X² - 54 X³ + 27 X⁴
0.268313 - 2.1465 X + 6.4395 X² - 8.586 X³ + 4.293 X⁴ = 4X²
0.268313 - 2.1465 X + 2.4395 X² - 8.586 X³ + 4.293 X⁴ = 0
Solving for X:
X = 0.1367. Right solution.
X = 1.8286. False solution. Produce negative concentrations
Replacing:
[N2] = 0.500M - 0.1367M
[H2] = 1.50M - 3*0.1367M
[NH3] = 2*0.1367M
The equilibrium concentrations are:
[N2] = 0.3633M
[H2] = 1.090M
[NH3] = 0.2734M