Consider the following reaction and its equilibrium constant: SO2(g) + NO2(g) ⇌ SO3(g) + NO(g) Kc = 0.33 A reaction mixture contains 0.39 M SO2, 0.14 M NO2 , 0.11 M SO3 and 0.14 M NO. Which of the following statements is TRUE concerning this system? a. The reaction quotient will decrease. b. The equilibrium constant will decrease. c. The reaction will shift in the direction of reactants. d. The reaction will shift in the direction of products. e. The system is at equilibrium.

d. The reaction will shift in the direction of products.

Explanation:

A reaction is in equilibrium when the Q = keq. If Q>keq, the reaction proceeds from products to reactants decreasing Q until Q>keq and vice versa.   keq never change if temperature remains constant. For the reaction:

SO₂(g) + NO₂(g) ⇌ SO₃(g) + NO(g)

Q is defined as:

Q = [NO] [SO₃] / [SO₂] [ NO₂]

Replacing:

Q = 0,14M×0,11M / 0,39M×0,14M

Q = 0,28

As Q < keq. Q increase. and the reaction proceed for reactants to products. Thus:

a. The reaction quotient will decrease. FALSE.

b. The equilibrium constant will decrease. FALSE

c. The reaction will shift in the direction of reactants. FALSE

d. The reaction will shift in the direction of products. TRUE

e. The system is at equilibrium. FALSE

I hope it helps!

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