Skip to main content
Ch.16 - Chemical Equilibrium
Tro - Chemistry: A Molecular Approach 6th Edition
Tro6th EditionChemistry: A Molecular ApproachISBN: 9780137832217Not the one you use?Change textbook
All textbooksTro 6th EditionCh.16 - Chemical EquilibriumProblem 55
Chapter 16, Problem 55

For the reaction shown here, Kc = 0.513 at 500 K. N2O4(g) ⇌ 2 NO2(g) If a reaction vessel initially contains an N2O4 concentration of 0.0500 M at 500 K, what are the equilibrium concentrations of N2O4 and NO2 at 500 K?

Verified step by step guidance
1
Set up the initial concentrations of the reactants and products. For N2O4, it is 0.0500 M, and for NO2, it is 0 M since it has not yet formed.
Let x be the change in concentration of N2O4 that reacts to reach equilibrium. The concentration of N2O4 at equilibrium will then be (0.0500 - x) M.
Since the reaction produces 2 moles of NO2 for every 1 mole of N2O4 that reacts, the concentration of NO2 at equilibrium will be (0 + 2x) M.
Write the expression for the equilibrium constant, Kc, in terms of the concentrations of the reactants and products at equilibrium. For the reaction N2O4(g) ⇌ 2NO2(g), Kc = \( \frac{[NO2]^2}{[N2O4]} \).
Substitute the equilibrium concentrations into the Kc expression and solve for x. Use the quadratic formula if necessary. Once x is found, substitute back to find the concentrations of N2O4 and NO2 at equilibrium.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
3m
Was this helpful?

Key Concepts

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

Equilibrium Constant (Kc)

The equilibrium constant, Kc, is a numerical value that expresses the ratio of the concentrations of products to reactants at equilibrium for a given reaction at a specific temperature. For the reaction N2O4 ⇌ 2NO2, Kc = [NO2]^2 / [N2O4]. A Kc value less than 1 indicates that at equilibrium, reactants are favored, while a value greater than 1 indicates that products are favored.
Recommended video:
Guided course
03:20
Equilibrium Constant Expressions

ICE Table

An ICE table (Initial, Change, Equilibrium) is a tool used to organize the concentrations of reactants and products at different stages of a chemical reaction. It helps in calculating the changes in concentration as the system reaches equilibrium. By filling in initial concentrations, the changes that occur during the reaction, and the equilibrium concentrations, one can solve for unknown values.
Recommended video:
Guided course
01:14
ICE Charts and Equilibrium Amount

Le Chatelier's Principle

Le Chatelier's Principle states that if a dynamic equilibrium is disturbed by changing the conditions, the system will adjust itself to counteract the change and restore a new equilibrium. This principle is useful in predicting how changes in concentration, pressure, or temperature will affect the position of equilibrium in a reaction, such as the one involving N2O4 and NO2.
Recommended video:
Guided course
07:32
Le Chatelier's Principle
Related Practice
Textbook Question

Silver sulfate dissolves in water according to the reaction: Ag2SO4(s) ⇌ 2Ag+(aq) + SO42-(aq) Kc = 1.1 * 10-5 at 298K A 1.5-L solution contains 5.14 g of dissolved silver sulfate. If additional solid silver sulfate is added to the solution, will it dissolve?

Textbook Question

For the reaction shown here, Kc = 255 at 1000 K. CO(g) + Cl2(g) ⇌ COCl2(g) If a reaction mixture initially contains a CO concentration of 0.1500 M and a Cl2 concentration of 0.175 M at 1000 K, what are the equilibrium concentrations of CO, Cl2, and COCl2 at 1000 K?

3268
views
1
rank
Textbook Question

Consider the reaction and the associated equilibrium constant: aA(g) ⇌ bB(g) Kc = 4.0 Find the equilibrium concentrations of A and B for each value of a and b. Assume that the initial concentration of A in each case is 1.0 M and that no B is present at the beginning of the reaction. c. a=1;b=2

2239
views
1
rank
Textbook Question

Consider the reaction: HC2H3O2(aq) + H2O(l) ⇌ H3O+(aq) + C2H3O2-(aq) Kc = 1.8⨉10-5 at 25°C If a solution initially contains 0.210 M HC2H3O2, what is the equilibrium concentration of H3O+ at 25 °C?

3717
views