At a certain temperature, the equilibrium constant $K_{c}$ is $0.36$ for the reaction
$S O_{2} (g) + N O_{2} (g) ⇌ S O_{3} (g) + NO (g) .$
If $1.8 mol$ of each of the four gases is added to a $1 L$ container, find the number of moles of $S O_{3} (g)$ at equilibrium.

Question

At a certain temperature, the equilibrium constant $K_{c}$ is $0.36$ for the reaction

$S O_{2} (g) + N O_{2} (g) ⇌ S O_{3} (g) + NO (g) .$

If $1.8 mol$ of each of the four gases is added to a $1 L$ container, find the number of moles of $S O_{3} (g)$ at equilibrium.

TestHub · Accepted Answer

Initially Q c ​ = ( 1.8 × 1.8 ) / ( 1.8 × 1.8 ) = 1 > 0.36 , so the equilibrium shifts left. If x moles react leftward, the reactants each become 1.8 + x and the products each become 1.8 − x . Therefore 0.36 = ( 1.8 + x ) 2 ( 1.8 − x ) 2 ​ , 0.6 = 1.8 + x 1.8 − x ​ , x = 0.45. The equilibrium amount of S O 3 ​ is 1.8 − 0.45 = 1.35 mol .

Chemistry - Chemical Equilibrium Question with Solution | TestHub

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