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

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1:16 minutes

Problem 52d

Textbook Question

Write the equilibrium constant expressions for the following reactions.
d. C(s) + H₂O(g) ⇌ CO(g) + H₂(g)

Verified step by step guidance

Identify the general form of the equilibrium constant expression, which is written as K = [products] / [reactants]. Concentrations of gases are expressed in terms of partial pressures or molar concentrations, while pure solids and liquids are not included in the expression.

Recognize that in the given reaction, C(s) is a solid. Since the equilibrium constant expression does not include pure solids, C(s) will not appear in the expression.

List the gaseous species in the reaction: H2O(g), CO(g), and H2(g). These are the species that will be included in the equilibrium constant expression.

Write the equilibrium constant expression as follows: K = ([CO][H2]) / [H2O], where [CO], [H2], and [H2O] represent the molar concentrations (or partial pressures) of the respective gases at equilibrium.

Ensure that the expression is balanced and reflects the stoichiometry of the reaction. In this case, all coefficients are 1, so no exponents are needed in the equilibrium constant expression.

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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 certain temperature and indicates the extent to which reactants are converted into products. A larger K value suggests a greater concentration of products at equilibrium, while a smaller K indicates a higher concentration of reactants.

Reaction Quotient (Q)

The reaction quotient (Q) is a measure of the relative concentrations of products and reactants at any point in time during a reaction. 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: if Q < K, the reaction shifts right to produce more products; if Q > K, it shifts left to produce more reactants.

Gaseous and Solid Reactants in K Expressions

In equilibrium constant expressions, only the concentrations of gaseous and aqueous species are included, while solids and pure liquids are omitted. This is because the activity of solids is considered constant and does not affect the equilibrium position. For the given reaction, only the gaseous products (CO and H2) and the gaseous reactant (H2O) will be included in the equilibrium expression, while the solid carbon (C) will not.