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Chemistry · EQUILIBRIUM
हिन्दीAt a certain temperature, the reaction \( A + B \rightleftharpoons C + D \) has an equilibrium constant \( K_c = 16 \). Initially, \( 1.0\text{ mole} \) of each of \( A, B, C, \) and \( D \) are placed in a \( 1.0\text{ L} \) flask. What will be the equilibrium concentration of species \( A \)?
Correct answer · Option 1
0.40 M
Explanation
Reaction quotient \( Q_c = (1\times 1)/(1\times 1) = 1 < 16 \), so forward reaction proceeds. At equilibrium, \( [A] = 1 - x \), \( [B] = 1 - x \), \( [C] = 1 + x \), \( [D] = 1 + x \). \( K_c = \frac{(1+x)^2}{(1-x)^2} = 16 \implies \frac{1+x}{1-x} = 4 \implies 1 + x = 4 - 4x \implies 5x = 3 \implies x = 0.60\text{ M} \). Therefore, \( [A] = 1.0 - 0.60 = 0.40\text{ M} \).
