Chemistry

When Q > K, the amount of the products must _____ and the amount of the reactants must _____ until equilibrium is established. The reaction will proceed toward the _____.

decrease; increase; reactants

If the value of K for the forward reaction is less than 1, the value of K for the reverse reaction is _____ than 1.

greater

As a reaction proceeds, the value of Q _____.

increases or decreases, as necessary, until it reaches the value of K

As a reaction proceeds toward equilibrium from reactants to products (i.e., from left to right as written), the value of Q is _____.

increasing

When a system reaches equilibrium, the ______ of the forward and reverse reactions are equal and the ratio of the forward over the reverse ______ equals the equilibrium constant, K.

rates; rate constants

When Q < K, the reaction will proceed so that the concentrations of the _____ decrease and the concentrations of the _____ increase.

reactants; products

The value of Kp for a given reaction is the equilibrium constant based on _____.

the partial pressures of the reactants and products

The value of K for the forward reaction is _____ the value of K for the reverse reaction.

the reciprocal of

Which of the following options correctly reflect the equation relating KP and Kc for a given reaction?

Δngas is determined from the coefficients of the balanced equation. T is the temperature in kelvin. R = 0.0821 atm⋅L/mol⋅K

Given the balanced equation 2PbO (s) + O2 (g) ⇌ 2PbO2 (s), calculate the value of Δngas.

-1

Match each quantity with the correct description.

-K = expresses a particular ratio of product and reactant concentrations for a reaction at equilibrium. -Q = expresses a particular ratio of product and reactant concentrations for a reaction at any time.

Which of the following options correctly describe the equilibrium constant K?

-K = kfwdk / krev for a system at equilibrium. -K expresses a particular ratio of equilibrium concentrations of products and reactants. -The value of K is characteristic of a particular equilibrium system.

Which of the following statements about the reaction quotient Q are correct?

-Q = K only at equilibrium. -Q expresses a particular ratio of products and reactants at any time during a reaction. -The expression for Q is the same as the expression for K.

Match the magnitude of the equilibrium constant K with the correct description of the reaction system.

-Small K = Equilibrium favors the reactants; there will be more reactants than products at equilibrium. -Intermediate K = Both reactants and products will be present in significant amounts at equilibrium. -Large K = Equilibrium favors the products; there will be more products than reactants at equilibrium.

Given the following data, what is the value of Kp for the reaction at 545 K? 2NO2Cl (g) ⇌ 2NO2 (g) + Cl2 (g), where Kc = 3.21 x 10-4 at 545 K

0.0144

Which of the following statements correctly describe the rate equations and rate constants for a system at equilibrium?

1. the ratio (products/reactants) remains constant although forward and reverse reactions are still occurring. 2. the rate of the forward reaction is equal to the rate of the reverse reaction.

For a given reaction, Kc is the equilibrium constant based on the molar ___ of reactants and products while Kp is the equilibrium constant based on the partial ___ of reactants and products.

Blank 1: concentrations or concentration Blank 2: pressures or pressure

The equilibrium constant K for a system at equilibrium expresses a particular ratio of equilibrium ___ of products and reactants at a particular ___. The value of K is also equal to the ratio of the rate ___ for the forward and reverse reactions.

Blank 1: concentrations or pressures Blank 2: temperature Blank 3: constants

The subscript "c" used in the symbols Qc and Kc indicates that these quantities are based on the ___ of products and reactants.

Blank 1: concentrations, molarities, concentration, molar concentrations, or molarity

In a closed system a reversible chemical reaction will reach a state of dynamic chemical ___ when the rate of the forward reaction is ___ to/than the rate of the reverse reaction.

Blank 1: equilibrium Blank 2: equal or equivalent

The law of mass action reflects the observation that an equilibrium state is reached by a chemical system regardless of the ___ concentrations of reacting substances. In other words, a chemical system can reach equilibrium either from the reactants or from the ___.

Blank 1: initial, starting, or beginning Blank 2: products

To construct the reaction quotient Qc for a given reaction, the ___ concentrations are placed in the numerator and the ___ concentrations are placed in the denominator. Each term is then raised to the power of its stoichiometric ___ from the balanced equation.

Blank 1: product Blank 2: reactant Blank 3: coefficient or number

The equilibrium constant is a special value of the reaction ___ that occurs when reactant and product concentrations are at their ___values.

Blank 1: quotient Blank 2: equilibrium

The concentrations of pure ___ and ___ are not included in the expression for Q or K for a given heterogeneous reaction.

Blank 1: solids Blank 2: liquids

Which of the following statements correctly describes a system at equilibrium for which K = 1.2?

Both products and reactants are present in significant amounts at equilibrium.

Which of the following statements correctly describe a chemical system at equilibrium? Select all that apply.

-The forward and reverse reactions occur at equal rates. -There is no longer a change in concentration of reactants and products over time.

The law of mass action states that _____.

-equilibrium can be reached from any direction, i.e., by beginning with a mixture of reactants or products, or both -a chemical system reaches a state where the concentrations of reactants and products is a constant ratio

For the reaction CO (g) + Cl2 (g) ⇌ COCl2 (g), Kp at 1000 K = 3.9 × 10-2. Which of the following options correctly reflect the steps required to calculate Kc at 1000 K? Select all that apply.

Delta-n=-1 Kc = (3.910^-2)(0.082061000)^1 = 3.2

Select the correct expression for the equilibrium constant of an overall reaction consisting of four reaction steps.

Koverall = K1 x K2 x K3 x K4

Which of the following is the correct expression for the relationship between Kc and KP?

Kp = Kc(RT)^Deltan/(gas)

Which of the following types of reactants and products do not appear in a reaction quotient expression for a heterogeneous reaction?

Pure solids Pure liquids

Match each relationship between Q and K for a given reaction to the correct direction in which the reaction will proceed.

Q < K = The reaction proceeds toward the products. Q = K = The system is at equilibrium, and no further net change occurs. Q > K = The reaction proceeds toward the reactants.

Which of the following symbols for Q denote the reaction quotient based on molar concentrations?

Qc

Select all the options that correctly reflect the steps required to determine the direction in which the following reaction will proceed at the given concentrations 2NO2Cl (g) ⇌ 2NO2 (g) + Cl2 (g), where Kc = 3.21 × 10-4 if [NO2Cl] = 0.012 M, [NO2] = 0.018 M, and [Cl2] = 0.026 M.

Qc = (0.026)(0.018)2 / (0.012)2 = 5.9 × 10-2 Since Qc > Kc, the reaction will proceed toward the reactants.

Which of the following is the correct expression for the reaction quotient for the overall reaction in a multistep process?

Qoverall = Q1 x Q2 x Q3 x...

In a given experiment, 0.10 atm of each component in the following reaction is placed in a sealed container. In which direction will the reaction proceed? 2NOBr (g) ⇌ 2NO (g) + Br2 (g) where KP = 60.6 at 100°C

The reaction proceeds toward the products.

If the equilibrium constant K for a particular reaction is 1.22 x 1014, which of the following statements correctly describes the reaction?

There are large concentrations of products compared to reactants.

The reaction quotient Qc for a particular reaction is given by the expression [X]a / [Y]b. Match the components of this expression correctly for the balanced equation 3O2 (g) ⇌ 2O3 (g).

X = O3 a = 2 Y = O2 b = 3

The value of the equilibrium constant K is a measure of how far the reaction proceeds toward the products at a given temperature. A small value of K indicates that the reaction favors the _____, whereas a large value of K indicates that the _____ will be present in a higher proportion.

reactants; products