Table of contents

1. Matter and Measurements4h 31m
2. Atoms and the Periodic Table5h 23m
3. Ionic Compounds2h 18m
4. Molecular Compounds2h 18m
5. Classification & Balancing of Chemical Reactions3h 17m
6. Chemical Reactions & Quantities2h 27m
7. Energy, Rate and Equilibrium3h 46m
8. Gases, Liquids and Solids3h 25m
9. Solutions4h 10m
10. Acids and Bases3h 29m
11. Nuclear Chemistry56m
BONUS: Lab Techniques and Procedures1h 38m
BONUS: Mathematical Operations and Functions47m
12. Introduction to Organic Chemistry1h 34m
13. Alkenes, Alkynes, and Aromatic Compounds2h 12m
14. Compounds with Oxygen or Sulfur1h 6m
15. Aldehydes and Ketones1h 1m
16. Carboxylic Acids and Their Derivatives1h 11m
17. Amines39m
18. Amino Acids and Proteins1h 51m
19. Enzymes1h 37m
20. Carbohydrates1h 41m
21. The Generation of Biochemical Energy2h 8m
22. Carbohydrate Metabolism2h 22m
23. Lipids2h 26m
24. Lipid Metabolism1h 45m
25. Protein and Amino Acid Metabolism1h 37m
26. Nucleic Acids and Protein Synthesis2h 54m

7. Energy, Rate and Equilibrium

The Equilibrium Constant

GOB Chemistry

7. Energy, Rate and Equilibrium

The Equilibrium Constant

Previous problemNext problem

1:21 minutes

Problem 51a

Textbook Question

Write the equilibrium constant expressions for the following reactions:
a. 2 CO(g) + O₂(g) ⇌ 2 CO₂(g)

Verified step by step guidance

Identify the general form of the equilibrium constant expression (Kc) for a chemical reaction. It is written as the ratio of the concentrations of the products raised to their stoichiometric coefficients to the concentrations of the reactants raised to their stoichiometric coefficients.

Write the equilibrium constant expression for the given reaction: \( 2 \text{CO}(g) + \text{O}_2(g) \rightleftharpoons 2 \text{CO}_2(g) \). The general form is \( K_c = \frac{[\text{products}]^{\text{coefficients}}}{[\text{reactants}]^{\text{coefficients}}} \).

Substitute the chemical species into the expression. The product is \( \text{CO}_2(g) \), and the reactants are \( \text{CO}(g) \) and \( \text{O}_2(g) \).

Raise the concentration of each species to the power of its stoichiometric coefficient. For \( \text{CO}_2(g) \), the coefficient is 2, so it becomes \( [\text{CO}_2]^2 \). For \( \text{CO}(g) \), the coefficient is 2, so it becomes \( [\text{CO}]^2 \). For \( \text{O}_2(g) \), the coefficient is 1, so it remains \( [\text{O}_2] \).

Combine these into the final equilibrium constant expression: \( K_c = \frac{[\text{CO}_2]^2}{[\text{CO}]^2[\text{O}_2]} \).

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Video duration:

Play a video:

Was this helpful?

Key Concepts

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

Equilibrium Constant (K)

The equilibrium constant (K) is a numerical value that expresses the ratio of the concentrations of products to reactants at equilibrium for a given chemical reaction. It is specific to a particular reaction at a specific temperature. A large K value indicates that products are favored at equilibrium, while a small K value suggests that reactants are favored.

Reaction Quotient (Q)

The reaction quotient (Q) is a measure of the relative amounts of products and reactants present in a reaction at any point in time. It is calculated using the same formula as the equilibrium constant but with the current concentrations. Comparing Q to K helps determine the direction in which a reaction will proceed to reach equilibrium.

Stoichiometry in Equilibrium Expressions

Stoichiometry refers to the coefficients of reactants and products in a balanced chemical equation, which are used to formulate the equilibrium constant expression. For the reaction 2 CO(g) + O2(g) ⇌ 2 CO2(g), the equilibrium expression is K = [CO2]^2 / ([CO]^2[O2]), where the concentrations are raised to the power of their respective coefficients, reflecting their proportions in the reaction.