7.1 Q vs K Continuous Improvement Project

What is the reaction quotient (Q)?

• A constant that depends on the initial amounts of the reactants and products in a reaction. It can be used to determine the direction of a reaction when compared with K.

• A constant that depends on the amounts of the reactants and products in a reaction at equilibrium. It can be used to determine the direction of a reaction when compared with K.

• A standard constant is provided on the formula sheet.

• A constant used determine the amount of energy released by a reaction.

What is the equilibrium constant (K)?

• A standard constant is provided on the formula sheet.

• A constant that depends on the amounts of the reactants and products in a reaction at equilibrium. When calculating, solids and liquids are omitted.

• A constant that depends on the initial amounts of the reactants and products in a reaction.

• A constant used determine the amount of energy released by a reaction.

Q and K Both (Choose all that apply):

• Are determined by dividing the products by the reactants

• Omit solids and liquids

• Utilize amounts at equilibrium

• Can be used to determine the direction of a reaction

A system reaches equilibrium when:

• There are equal amounts of every substance.

• The amounts of each substance stabilize and stop changing over time

• All substances begin decreasing except one

• All substances begin increasing except one

If Q is less than K in a reaction the reaction will shift towards

• The Left

• The Right

• The Products

• The Reactants

[CARDS QUESTION #1]

If the equilibrium constant A + B <--> C is 0.389, then the equilibrium constant for 4C <--> 4A + 4B is

• 0.156
• 0.789
• 43.7

• 1.000

[CARDS QUESTION #2]

At what point in time does the system shown reach equilibrium?

• When the lines intersect.

• When the lines stabilize.

• When the lines are decreasing.

• When the lines are increasing.

[CARDS QUESTION #3]

What is the correct equilibrium constant expression for the reaction H2 + I2 ⇌ 2HI?

• Kc = [H2]^2[I2] / [HI]
• Kc = [HI]^2 / ([H2][I2])
• Kc = [HI] / ([H2]^2[I2])
• Kc = [H2][I2] / [HI]^2

[CARDS QUESTION #4]

When does the reaction depicted first reach equilibrium?

• When the forward and backward reaction rates become the same.

• When the catalyst is added.

• At time = 0

• Equilibrium is never reached.

Calculate the value of Kc for the reaction:  

2NO(g) + Br2(g) ⇄ 2NOBr (g) 

using the following information.

2 NO(g) ⇄ N2(g) + O2(g)                   Kc1 = 1 x 10^30

N2(g) + Br2(g) + O2(g) ⇄ 2NOBr(g)   Kc2 = 2 x 10^-27

• 2 x 10^3

• 3 x 10^-28
• 5 x 10^-2
• 1 x 10^-30