Answer
Since $Q_c \ne K_c$, the mixture is not at equilibrium, and the compounds cannot be maintained indefinitely at these concentrations.
Work Step by Step
1. Calculate all the concentrations:
$$[SO_2] = ( 3.6 )/(7.2) = 0.50 M$$
$$[O_2] = ( 2.2 )/(7.2) = 0.31 M$$
$$[SO_3] = ( 1.8 )/(7.2) = 0.25 M$$
- The exponent of each concentration is equal to its balance coefficient.
$$Q_c = \frac{[Products]}{[Reactants]} = \frac{[ SO_3 ] ^{ 2 }}{[ SO_2 ] ^{ 2 }[ O_2 ]}$$
2. Substitute the values and calculate the quocient value:
$$Q_c = \frac{( 0.25 )^{ 2 }}{( 0.50 )^{ 2 }( 0.31 )} = 0.81$$
Since $Q_c \ne K_c$, the mixture is not at equilibrium, and the compounds cannot be maintained indefinitely at these concentrations.
