Fundamentals of Equilibrium

Which of the following best describes the term homogeneous equilibrium?

Homogeneous equilibrium is the equilibrium in a system in which all reactants and products are present in a single phase.

Consider the reaction below. If the initial concentration of the products C and D are both 0M, and at equilibrium the concentration of D increases by 0.037 M, how does the concentration of C change? 3A(g)+4B(g)⇋2C(g)+D(g)

It increases by 0.074 M

What will be the value of Kp in terms of Kc for the following equilibrium: A(g)+2B(g)→3C(g)+D(g)

Kc(RT)

Which of the following is NOT true regarding a system in equilibrium?

Only the concentration of the reactants is constant.

What will be the Kp for the following equilibrium: Cl2(l)→Cl2(g)

PCl2(g)

What is the reaction quotient for the reversible reaction shown below? P4(s)+5O2(g)⇌P4O10(s)

Qc = 1 / [O2]^5

The law of mass action best fits which of the following descriptions?

The law of mass action is the statement that the reaction quotient remains constant when a reversible reaction has attained equilibrium at a given temperature.

Find the reaction quotient for the reversible reaction below. 2CO2(g)⇌2CO(g)+O2(g)

[CO]^2[O2] / [CO2]^2

Write the expression for the reaction quotient in terms of concentration for the following reaction. 3H2+N2↽−−⇀2NH3

[NH3]^2 / [N2][H2]^3

Given the reaction below, what is the reaction quotient? 2KClO3(s)⇌2KCl(s)+3O2(g)

[O2]^3

An ICE chart is needed to calculate Kc if:

a combination of initial concentrations and at least one equilibrium concentration are given

Based on the reaction below, how will the concentration of D change if the concentration of C decreases by 0.053 M? 2A(aq)+5B(aq)⇋5C(aq)+D(aq)

decreases by .011 M

Q is always

dependent on the reaction and its progress.

Which type of equilibrium is more likely to omit substances from the equilibrium constant expression?

heterogeneous equilibria

As a reaction proceeds in the forward direction, Q will:

increase

Given the reaction below, how will the concentration of D change if the concentration of B decreases by 0.045 M? 3A(g)+2B(g)⇋2C(g)+5D(g)

increases by .113M

The value of the equilibrium constant, Kc, for a reaction will be __________.

independent of initial concentrations

When converting between Kc and Kp, this relationship will depend on the change in:

moles of gas between reactants and products

Substances on opposite sides of the equilibrium will have relative changes in concentration that are of:

opposite sign

Homogeneous equilibria will typically not exist in the:

solid phase

The relative changes in concentration of the substances involved in an equilibrium as the system equilibrates can be determined by looking at the:

stoichiometry of the equilibrium

Complete the set of algebraic terms representing the changes in concentrations for the following reaction: 2NO+O2 ⇌ 2NO2

x, 12x, −x

What will be the value of Kp in terms of Kc for the following equilibrium: 2A(g)+B(g)⇋3C(g)

Kc

The ideal gas constant is symbolized as:

R

Kc expressions will exclude:

solids

It can be difficult to differentiate a system at equilibrium from a system containing a:

very slow chemical reaction

Which of the following demonstrate homogeneous equilibria? (select all that apply)

- A reaction occurring in a liquid-phase solution - A reaction involving exclusively gaseous species - A reaction between solutes in liquid solution

Which of the following are true statements regarding reversible reactions?

- A reversible reaction might proceed in only one direction, with negligible contribution from the reverse reaction, depending on conditions. - The forward and reverse reactions may occur simultaneously.

The ideal gas law displays the relationship in which of the following? Select all that apply.

- Amontons's law - Charles's law - Boyle's law - Avogadro's law

Which of the following are reactions demonstrating heterogeneous equilibria? (select all that apply)

- Ca(OH)2(s)⇄Ca2+(aq)+2OH−(aq) - H2O(l)⇄H2O(g)

Identify the options below that are false about chemical equilibria. (select all that apply)

- Concentrations of products and reactants oscillate between a set range of values. - At equilibrium, all species have stopped reacting altogether.

Which of the following are examples of heterogeneous equilibria? (select all that apply)

- a reaction involving both gases and liquids - a reaction involving a solid and a liquid

For the following equilibrium: A+2B⇋C+3D If the change in concentration for B is 0.44 M, what will be the change in concentration for C?

-.22

For the following equilibrium: 2A+B→C+2D If the change in concentration for C is 0.36 M, what will be the change in concentration for A?

-.72

Consider the reaction described by the equation below. 4A(g)+5B(g)⇌5C(g)+2D(g) If the initial concentrations of A and B are both equal to 0.100M and the equilibrium concentration of B is 0.0840 M, what is the equilibrium concentration of D?

.0064 M

At equilibrium for the reaction in aqueous medium below, the concentrations of A, B, C, and D are 0.011 M, 0.0067 M, 0.0124 M, and 0.0062 M, respectively. What is the equilibrium constant? A+2B⇌3C+D

.024

Consider the reaction below. If the concentration of C decreases by 0.088 M, what will be the change in concentration for A? 2A(g)+3B(g)⇋5C(g)+4D(g)

.035 M

Consider the reaction below. At equilibrium, the concentration of A is 0.0502 M and the concentration of B is 0.057 M. If the equilibrium constant is Kc=3.8038, what is the equilibrium concentration of C? 2A(aq)+B(aq)⇌3C(aq)

.082 M

Consider the reaction below. If the concentration of B decreases by 0.068 M, what will be the change in concentration for C? 3A(g)+4B(g)⇋5C(g)

.085

Given the reaction below, if the concentration of B increases by 0.060 M, what will the be the change in concentration of A? 4A(g)+2B(g)⇋3C(g)+D(g)

.120 M

Based on the reaction below, if the concentration of B increases by 0.0830 M, what will be the change in concentration for A? 4A(g)+2B(g)⇋C(g)+2D(g)

.166

Based on the reaction below, if the concentration of D decreases by 0.0430 M, what will be the change in concentration for A ? 4A(g)+2B(g)⇋5C(g)+D(g)

.172 M

For the equilibrium C2H2+2Br2⇌C2H2Br4 if the initial concentrations are [C2H2]=0.80 M,[Br2]=1.60 M,[C2H2Br4]=0.55 M, and the reaction proceeds in the forward direction until equilibration, where [C2H2]=0.60 M, what is the final concentration (in units of molarity) of C2H2Br4?

.75 M

For the following equilibrium: 2A+B↽−−⇀C+2D If equilibrium concentrations are [A]=1.5 M, [C]=1.1 M, and [D]=0.68 M, and Kc=0.27, what is the equilibrium concentration of B?

.84 M

or the following equation, what is the equation for the reaction quotient? PCl3(l)+Cl2(g)⇌PCl5(s)

1 / [CL2]

For the following equilibrium: C2H2+2Br2⇌C2H2Br4 If the initial concentrations are: [C2H2]=0.25 M,[Br2]=0.50 M,[C2H2Br4]=2.5 M, and the reaction proceeds in the reverse direction until equilibration, where [C2H2Br4]=2.15 M, what is the final concentration of Br2?

1.2 M

What are possible algebraic terms representing the relative changes in concentrations for the following reaction? 2SO2+O2↔2SO3

2x, x, −2x