During a chemical reaction, the reactant(s) present are gradually transformed into products. This transformation takes place at a given rate.
-
Chemical kinetics is a field of chemistry that studies the rate of chemical reactions.
-
The reaction rate is the change in the quantity of reactants or products over time.
The reaction rate is generally measured in moles per litre second |(\text{mol/L}{\cdot\text{s}}).| It can also be measured in other units, depending on the method used in the laboratory to determine the reaction rate. There are therefore several types of mathematical equations for expressing the reaction rate.
By studying the rate of a reaction under different conditions (temperature, pressure, etc.), we can determine how to manipulate the rate of a reaction. Models can also be developed to explain how reactants are transformed into products.
The following examples illustrate different applications of chemical kinetics.
Ammonia |(\text{NH}_3)| is an essential compound for agriculture. It is used in the synthesis of many nitrogen fertilizers, a family of fertilizers that provides plants with the nitrogen essential for their development.
Ammonia can be synthesized using the Haber process, according to the following chemical equation.
|\text{N}_{2{\text{(g)}}} + 3\text{H}_{2{\text{(g)}}} \rightarrow 2\text{NH}_{3{\text{(g)}}}|
Chemical kinetics has been used to maximize the efficiency of this process by studying the factors that influence the speed of this reaction.
Source: encierro, Shutterstock
Pharmacokinetics is a field of expertise that studies the kinetic properties of drugs. For example, we can determine how quickly a drug is absorbed by the body, how quickly it acts and how quickly it is then eliminated.
For example, the drug Digoxin is used to treat certain heart conditions. Since its rate of absorption by heart cells is low, we know that the compound will take time to act and produce the desired effects.
