Reaction Quotient

For the reaction: 2 CO₂ (g)  ⇌ 2 CO (g) + 2 O₂  (g), the equilibrium constant is 3.12 × 10⁻⁴ at 400 K, while the reaction quotient is 4.18 × 10⁻⁴. If initially we have 0.20 atm CO₂, 0.30 atm CO and 0.15 atm O₂, which of the following statements is not true? 

a) The pressure of CO₂ will be greater than 0.20 atm. 

b) The pressure of CO will be less than 0.30 atm. 

c) The pressure of O₂ will be greater than 0.15 atm. 

d) The pressure of O₂ will be less than 0.15 atm. 

e) The reaction will favor reactants. 

• A. The pressure of CO₂ will be greater than 0.20 atm.
• B. The pressure of CO will be less than 0.30 atm.
• C. The pressure of O₂ will be greater than 0.15 atm.
• D. The pressure of O₂ will be less than 0.15 atm.
• E. The reaction will favor reactants.

The equilibrium constant for the following gas phase reaction is 0.75 at 750 K. After a short time, analysis of a small amount of the reaction mixture shows the concentrations to be [NOBr] = 1.25 M, [NO] = 0.80 M and [Br₂] = 0.50 M. Which of the following statements is/are true? 

2 NOBr (g)  ⇌ NO (g) + Br₂ (g)

a) The reaction mixture is at equilibrium. 

b) No further reaction will occur. 

c) The partial pressure of NOBr will increase. 

d) The partial pressure of NO will increase. 

e) The reaction will shift to the left, the reactant side. 

• A. The reaction mixture is at equilibrium.
• B. No further reaction will occur.
• C. The partial pressure of NOBr will increase.
• D. The partial pressure of NO will increase.
• E. The reaction will shift to the left, the reactant side.