Dynamic Equilibrium

Part of the Energy, Rates and Equilibrium section of Coddy's Chemistry journey. Lesson 22 of 35.

In a closed flask N₂O₄ splits into NO₂ and NO₂ joins back. Soon both run at the same rate.

A container of colourless N2O4 turns brown as NO2 forms, until the colour stops changing

At equilibrium both directions run at the same rate

Dynamic equilibrium: both reactions go on, the amounts stay the same.

Amounts follow the equation: one N₂O₄ split makes two NO₂.

Challenge

A sealed flask starts with $1.0\ \mathrm{mol}$ of N₂O₄. When the colour stops changing, $0.6\ \mathrm{mol}$ of N₂O₄ is left. How many moles of NO₂, n_B, are there? N₂O₄ ⇌ 2NO₂.

Try it yourself

Solve for $n_{B}$

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Energy, Rates and Equilibrium

1Energy in Reactions

Exothermic and Endothermic Energy Diagrams Enthalpy Change Activation Energy Recap - Hand Warmer

4Rates of Reaction

Collision Theory Concentration and Rate Temperature and Rate Surface Area Catalysts Recap - Speed Trials

7Practice Problems

Recap - Methanol Plant Recap - Butane Lighter Recap - Limestone Kiln

2Bond Energies

Breaking and Making Bonds Delta H from Bond Energies Hess's Law Energy and Moles Recap - Fuel Value

5Equilibrium

Reversible ReactionsDynamic EquilibriumThe Equilibrium Constant Writing K Solids and Liquids in K Recap - K Builder

3Changes of State

Heating Curves Melting and Boiling Energy of State Changes Recap - Ice to Steam

6Changing an Equilibrium

Le Chatelier's Principle Changing Concentration Changing Pressure Changing Temperature The Haber Process Recap - Factory Settings