Question

The following reaction mixture contains 0.22 M CH4, 0.67 M CO2 and 1.3 M H2O. Which of the following statements is TRUE concerning this system?
4 CuO(s) + CH4(g) ? CO2(g) + 4 Cu(s) + 2 H2O(g)
Kc = 1.10
a)the reaction is running fastest toward the reactants
b)the reaction is running fastest toward the products
c)the value of the equilibrium constant will increase
d)the value of the reaction quotient will increase
e)the reaction is at equilibrium

Answer 1

Answer:

Reaction is shifting left toward reactant side

Explanation:

4CuO(s) + CH₄(g) <=?=> CO₂(g) + Cu(s) + 2H₂O(g)

---------      0.22M             0.67M     -------    1.30M

Qc = [O₂(g)][H₂O(l)]²/[CH₄(g)] = (0.67)(1.30)²/(0.22) =5.12

Kc = 1.1 < Qc = 5.12 => Reaction is shifting LEFT and reactant concentrations are increasing with product concentrations decreasing. Qc will be decreasing and final Kc value will be lower than original Qc upon reaching equilibrium stability.  

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FYI Note => For reaction mixtures the following is a good guide to reaction response to applied system stress. Note the conclusion follows the direction the inequality symbol is pointing.  

Kc  <  Qc  => Rxn system is shifting Left

Kc =   Qc  => Rxn system is at equilibrium

Kc >  Qc  => Rxn system is shifting Right