Consider the reaction: A2 + B2 <--> 2AB. The reactants are mixed together, and the following is a plot of the reactant and the product concentrations with time. If at equilibrium, the concentration of A2 is 0.5 M, B2 is 0.5 M, and AB is 1.0 M, what is the value of the equilibrium constant K?

• A. 4
• B. 1/2
• C. 1
• D. 2

Answer: (D)

Verified step by step guidance

1. Understand the concept of equilibrium constant (K). It is a ratio of the concentration of products to reactants at equilibrium, each raised to the power of their stoichiometric coefficients.
2. Write the expression for the equilibrium constant (K) for the given reaction: A2 + B2 ⇌ 2AB. The expression is: $K=\frac{[\mathrm{AB}{]}^2}{\left[A_2\right]\left[B_2\right]}$
3. Substitute the equilibrium concentrations into the expression. Given: [A2] = 0.5 M, [B2] = 0.5 M, [AB] = 1.0 M.
4. Calculate the value of K using the substituted values: $K=\frac{\left(1.0\right)2^{}}{\left(0.5\right)\left(0.5\right)}$
5. Simplify the expression to find the value of K. This involves squaring the concentration of AB and multiplying the concentrations of A2 and B2.