Skip to main content
Pearson+ LogoPearson+ Logo
Ch.15 - Chemical Equilibrium
All textbooksBrown 14th EditionCh.15 - Chemical EquilibriumProblem 41b
Chapter 15, Problem 41b

(b) What condition must be satisfied so that Qc = Kc?

Verified step by step guidance
1
<Q_c> and <K_c> are both expressions that describe the ratio of the concentrations of products to reactants for a given chemical reaction.
The reaction quotient, <Q_c>, is calculated using the concentrations of the reactants and products at any point in time, not necessarily at equilibrium.
The equilibrium constant, <K_c>, is calculated using the concentrations of the reactants and products at equilibrium.
For <Q_c> to equal <K_c>, the system must be at equilibrium, meaning the concentrations of reactants and products have reached a state where they no longer change with time.
Therefore, the condition that must be satisfied for <Q_c> = <K_c> is that the reaction mixture is at equilibrium.

Verified Solution

Video duration:
53s
This video solution was recommended by our tutors as helpful for the problem above.
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Reaction Quotient (Q<sub>c</sub>)

The reaction quotient, Q<sub>c</sub>, is a measure of the relative concentrations of products and reactants at any point in a chemical reaction. It is calculated using the same expression as the equilibrium constant but with the current concentrations. Q<sub>c</sub> helps determine the direction in which a reaction will proceed to reach equilibrium.
Recommended video:
Guided course
00:49
Reaction Quotient Q

Equilibrium Constant (K<sub>c</sub>)

The equilibrium constant, K<sub>c</sub>, is a value that expresses the ratio of the concentrations of products to reactants at equilibrium for a reversible reaction at a given temperature. It is a fixed value for a specific reaction under specific conditions, indicating the extent to which reactants are converted into products at equilibrium.
Recommended video:
Guided course
01:14
Equilibrium Constant K

Dynamic Equilibrium

Dynamic equilibrium occurs in a reversible reaction when the rates of the forward and reverse reactions are equal, resulting in constant concentrations of reactants and products. At this point, Q<sub>c</sub> equals K<sub>c</sub>, indicating that the system is balanced and no net change occurs. This condition is essential for understanding when a reaction has reached equilibrium.
Recommended video:
Guided course
01:18
Chemical Equilibrium Example
Related Practice
Open Question
A flask is charged with 1.500 atm of N2O4 and 1.00 atm NO2 at 25 _x001F_C, and the following equilibrium is achieved: N2O4(g) β‡Œ 2 NO2(g). After equilibrium is reached, the partial pressure of NO2 is 0.512 atm. (b) Calculate the value of Kp for the reaction. (c) Calculate Kc for the reaction.
Open Question
Two different proteins X and Y are dissolved in aqueous solution at 37 _x001F_C. The proteins bind in a 1:1 ratio to form XY. A solution that is initially 1.00 mM in each protein is allowed to reach equilibrium. At equilibrium, 0.20 mM of free X and 0.20 mM of free Y remain. What is Kc for the reaction?
Textbook Question

(a) If Qc < Kc, in which direction will a reaction proceed in order to reach equilibrium?

546
views
Textbook Question

(a) If Qc > Kc, how must the reaction proceed to reach equilibrium?

874
views
Textbook Question

(b) At the start of a certain reaction, only reactants are present; no products have been formed. What is the value of Qc at this point in the reaction?

595
views
Textbook Question

At 100Β°C, the equilibrium constant for the reaction COCl2(𝑔) β‡Œ CO(𝑔) + Cl2(𝑔) has the value 𝐾𝑐 = 2.19Γ—10βˆ’10. Are the following mixtures of COCl2, CO, and Cl2 at 100Β°C at equilibrium? If not, indicate the direction that the reaction must proceed to achieve equilibrium. (a) [COCl2] = 2.00Γ—10βˆ’3 𝑀, [CO] = 3.3Γ—10βˆ’6 𝑀, [Cl2] = 6.62Γ—10βˆ’6𝑀

736
views