2A (g) + Y (g) <-- --> 3C (g) + D (g) Based on the initial conditions shown below, determine the value of the equilibrium constant if the concentration of product C at equilibrium was measured to be 0.456 M.
Initial Conditions: No reactants present, [C] = 0.651 M, [D] = 0.754 M.
Equilibrium Conditions: [A] = ?, [Y] = ?, [C] = 0.456 M, [D] = ?.

A. K = 59.5
B. K = 37.2
C. K = 0.0269
D. K = 0.0168

A. K = 59.5

Explanation:

Hello there!

In this case, since this reaction seems to start moving leftwards due to the fact that neither A nor Y are present at equilibrium, we should rewrite the equation:

3C (g) + D (g) <-- --> 2A (g) + Y (g)

Thus, the equilibrium expression is:

Next, according to an ICE table for this reaction, we find that:

Whereas x is calculated by knowing that the [C] at equilibrium is 0.456M; thus:

Next, we compute the rest of the concentrations:

Thus, the equilibrium constant for the leftwards reaction is:

Nonetheless, we need the equilibrium reaction for the rightwards reaction; thus, we take the inverse to get:

Therefore, the answer would be A. K = 59.5.

Regards!