Collections:Texts:Chemistry:Chapter 18 - Chemical Kinetics
From ChemEd Collaborative
CHEMICAL KINETICS
18.1 Experimental Measurement of Rates
18.2 Microscopic View of Chemical Reactions
18.4 Increasing the Rate of a Reaction
18.5 Some Important Types of Catalysts
Chemical kinetics is concerned with the rates of chemical reactions, that is, whether reactions proceed quickly or slowly. As we have already mentioned, some spontaneous reactions are extremely slow. An example is the Haber-process synthesis of ammonia:
- N2 + 3H2 → 2NH3 ΔGm°(298 K) = – 33.27 kJ mol–1
Even though a negative ΔGm° predicts that this reaction can occur at room temperature, it is of little value unless chemists can find some way to speed it up. On the other hand we often want to slow down undesirable reactions, such as spoilage of food or decomposition of wood. Hence it is quite useful to know how factors such as temperature, concentrations of reactants and products, and catalysts will affect the rates of reactions. Moreover, studying these factors gives valuable information about the sequence of microscopic events by which a reaction occurs. Knowledge of when and where bonds are formed and broken as well as how molecular structures change during a reaction can be very useful in helping us to devise ways to speed up or slow down that reaction.
Go to previous | Go to start of chapter | Return to Table of Contents | Go to next
