Concentration and Rate

Part of the Energy, Rates and Equilibrium section of Coddy's Chemistry journey. Lesson 16 of 35.

More concentrated: more particles per liter, more collisions, a faster reaction.

As reactants are used up the reaction slows: the curve is steep, then flat.

Volume of gas collected against time: it rises steeply at first, then levels off near 60 mL

Gas collected over time: fast at first, slower as the reactants run out

Average rate between two moments:

$r = \frac{V_2 - V_1}{t_2 - t_1}$

Challenge

Marble chips react with acid and give off carbon dioxide. After $4\ \mathrm{min}$ , $48\ \mathrm{mL}$ of gas has been collected. What is the average rate $r$ over those four minutes?

Try it yourself

Solve for $r$

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 TheoryConcentration and RateTemperature 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 Reactions Dynamic Equilibrium The 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