Chemistry: Quiz: Equilibrium Concentrations

Quiz: Equilibrium Concentrations

1. The equilibrium constant is always written as a ratio of

a. products over reactants

b. reactants over products

c. products times reactants

2. When writing an equilibrium expression, the coefficients from the balanced equation become the

a. factors of the concentration terms

b. exponents of the concentration terms

c. divisor of the concentration terms

3. In a K_c expression, the concentrations of the species are expressed in terms of

a. molality

b. mole fraction

c. molarity

4. In a K_p expression, the concentrations of the gaseous species are expressed in terms of

a. pressure

b. molality

c. molarity

5. A large equilibrium constant value means that the

a. reaction is favoring the reactants

b. reaction is favoring the products

c. reaction is at completion

6. If the reverse reaction is favored, the K value for the reverse reaction will be

a. more than the K value for the forward reaction

b. the same as the K value for the forward reaction

c. less than the K value for the forward reaction

7. At a particular temperature, how many equilibrium constants can exist?

a. 2

b. 1

c. 0

8. The brackets ([ ]) used in an equilibrium constant expression represent

a. the physical state of the species

b. the concentration of the species at STP

c. the concentration of the species in terms of molarity

9. While all different types of physical states can be present in a chemical equation, the incorporation of __________ are not expressed in the equilibrium constant expression.

a. gases

b. solids and liquids

c. aqueous solutions

Use the following reaction for questions 10–13

10. At equilibrium, the following concentrations exist: [H₂] = 1.14 × 10^–2 M; [I₂] = 1.20 × 10^–3 M; and [HI] = 2.52 × 10^–2 M. Calculate the equilibrium constant for this reaction.

a. 0.215

b. 46.4

c. 1842

11. If additional I₂( g) is added to the reaction vessel, the equilibrium will

a. shift to the right

b. shift to the left

c. remain at the same concentrations

12. If K_c = 50.0 and the [H₂] = [I₂] = 8.6 × 10^–3 M, what will be the concentration of HI?

a. 1.2 × 10^–3 M

b. 0.43 M

c. 6.1 × 10^–2 M

13. If the K_p = 54.4 and the P_HI = 0.800 atm, determine the pressures of H₂ and I₂ at equilibrium.