MED-102 General Chemistry: Chemical Equilibrium 1

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the correct expression for the equilibrium constant Kc for the reaction CaCO3(s) ⇌ CaO(s) + CO2(g)?

Kc = [CaCO3]/[CaO][CO2]

Kc = [CaO][CO2]/[CaCO3] (correct)

Kc = [CaO][CO2]

Kc = [CaCO3]

Which statement correctly describes the relationship between Kp and Kc?

Kp = Kc (RT) for all reactions.

Kp and Kc are equal only at standard conditions. (correct)

Kp is always greater than Kc.

Kc = Kp when the reaction involves only pure solids.

How is a heterogeneous equilibrium different from a homogeneous equilibrium?

Heterogeneous equilibrium includes only gases.

Heterogeneous equilibrium only involves liquids.

Heterogeneous equilibrium includes both solids and gases. (correct)

Heterogeneous equilibrium has constant concentrations.

In the reaction 2 H2(g) + O2(g) ⇌ 2 H2O(g), if Kc = 2.4 × 10^47 at 500°C, what does this Kc value indicate about the equilibrium position?

Equilibrium lies to the right. Signup and view all the answers

Which of the following is NOT considered when calculating the equilibrium constant Kc?

Pure solids Signup and view all the answers

What happens to the direction of a reaction when Qc < Kc?

The reaction will move to the right. Signup and view all the answers

Which components are included in the equilibrium constant Kc expression?

Only gases and aqueous solutions. Signup and view all the answers

What is the Kc value for the reaction at 700 K given the expression H2(g) + I2(g) ⇌ 2 HI(g)?

57.0 Signup and view all the answers

What occurs at dynamic equilibrium in a chemical reaction?

The rates of the forward and reverse reactions are equal. Signup and view all the answers

How is Kp related to Kc mathematically?

Kp can be derived from Kc using the ideal gas law. Signup and view all the answers

What does it mean if Qc > Kc for a given reaction?

The reaction will move to the left. Signup and view all the answers

Which of the following correctly describes homogeneous equilibria?

Contain reactants and products in the same phase. Signup and view all the answers

What defines the state of dynamic equilibrium in a chemical reaction?

Both forward and reverse reactions occur at equal rates. Signup and view all the answers

Which condition is essential for establishing dynamic equilibrium?

There must be both forward and reverse reactions. Signup and view all the answers

Which of the following correctly describes how to write an equilibrium expression for the reaction A + B ⇌ C + D?

K = [C][D]/[A][B] Signup and view all the answers

How is the equilibrium constant Kc related to Kp for a gas-phase reaction?

Kp is related to Kc by the equation Kp = Kc (RT) ^ Δn. Signup and view all the answers

If a system at equilibrium is disturbed by changing the concentration of reactants, what will happen?

The equilibrium will shift to the right to produce more products. Signup and view all the answers

In a heterogeneous equilibrium, which of the following statements is true?

Only gaseous and aqueous substances appear in the equilibrium expression. Signup and view all the answers

What will occur if the temperature of an exothermic reaction at equilibrium is increased?

The equilibrium will shift to the right, favoring reactants. Signup and view all the answers

For a reaction involving gases, if Kp = 0.01 at a certain temperature, what does this indicate about the reaction?

The concentration of reactants is greater than that of products. Signup and view all the answers

Which of the following is an example of a system likely to reach dynamic equilibrium?

A beaker of water evaporating into the air. Signup and view all the answers

Study Notes

Course Information

Course: MED-102 General Chemistry
Topic: Chemical Equilibrium 1

Learning Objectives (LOBs)

Describe dynamic equilibrium
Write equilibrium expressions
Calculate K from K_p and vice versa
Predict the direction of a chemical system to establish equilibrium

What is Chemical Equilibrium?

Chemical kinetics focuses on reaction speed ("how fast?")
Chemical equilibrium focuses on the extent of a reaction ("how far?")
Equilibrium is the state where reactant and product concentrations remain constant
The resulting mixture is called the "equilibrium mixture"
Equilibrium applies only to reversible reactions

Dynamic Equilibrium

Forward and reverse reactions continue
Rates of forward and reverse reactions are equal
No net change in reactant or product amounts

The Equilibrium State

Many reactions don't proceed to completion due to reverse reactions
Equilibrium can be reached from either reactant or product side
At a given temperature, the same equilibrium mixture will be reached

The Equilibrium Constant K_c

K_c is the equilibrium constant based on concentrations
Its formula: K_c = [C]^c[D]^d / [A]^a[B]^b
Subscript 'c' refers to concentrations (molarities)

Equilibrium Constant K_p

K_p is the equilibrium constant based on partial pressures
Its formula: K_p = (P_C)^c(P_D)^d / (P_A)^a(P_B)^b
For gaseous systems

Relating K_c to K_p

K_p = K_c(RT)^Δn
Δn = moles of gaseous products - moles of gaseous reactants
Equilibrium constants (K_c and K_p) are unitless

Heterogeneous Equilibria

Reactants and products are in different phases
Pure solids and liquids do not appear in the equilibrium expression

Using the Equilibrium Expression

Calculate reaction quotients (Q)
Compare Q to K to predict reaction shift
Q < K: reaction shifts right to reach equilibrium
Q > K: reaction shifts left to reach equilibrium
Q = K: reaction is at equilibrium

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz covers key concepts of chemical equilibrium, including dynamic equilibrium and equilibrium expressions. Students will learn to calculate equilibrium constants and predict the direction of reactions. Test your understanding of reversible reactions and the equilibrium state.