Answer:
The answer to your question is d. 0.5 M
Explanation:
Data
[A] = 1M
K = 0.5
Concentration of B and C at equilibrium = x
Concentration of A at equilibrium = 1 - x
Equation of equilibrium
k = [tex]\frac{[B][C]}{A}[/tex]
Substitution
[tex]0.5 = \frac{[x][x]}{1 - x}[/tex]
Simplification
0.5 = [tex]\frac{x^{2}}{1 - x}[/tex]
Solve for x
0.5(1 - x) = x²
0.5 - 0.5x = x²
x² + 0.5x - 0.5 = 0
Find the roots x₁ = 0.5 x₂ = -1
There are no negative concentrations so the concentration of A at equilibrium is
[A] = 1 - 0.5
= 0.5 M