Chemical equilibrium

CHEMICAL EQUILIBRIUM

Schoolgirl : Azuaje S. Roxi A. C.I : 23304387 School: 49, Chemical Engineering

Chemical equilibrium is the condition which occurs when the concentration of reactants and products participating in a chemical reaction exhibit no net change over time. Chemical equilibrium may also be called a "steady state reaction." This does not mean the chemical reaction has necessarily stopped occurring, but that the consumption and formation of substances has reached a balanced condition. The quantities of reactants and products have achieved a constant ratio, but they are almost never equal. There may be much more product or much more reactant.

Explain the dynamic nature of chemical equilibrium and classify the different types of equilibrium chemicals

Chemical Dynamics is one of the three areas of chemistry as the Westheimer Report (1965), together with the structural chemistry and synthetic chemistry. Its objective is the analysis of chemical processes from an evolutionary dimension, ie, it deals with the study of matter in the process of chemical change, and the causes of these processes.

Express the factors affecting the chemical equilibrium

Le Chatelier's Principle is an observation about chemical equilibria of reactions. It states that changes in the temperature, pressure (or volume), or concentration of a system will result in predictable and opposing changes in the system in order to achieve a new equilibrium state. Le Chatelier's Principle can be used in practice to understand reaction conditions that will favor increased product formation. This idea was discovered and formulated independently

by Henri Louis Le Chatelier (pictured below) and Karl Ferdinand Braun.

Interpret calculate equilibrium constants and free energy changes

Under conditions of constant temperature and pressure, chemical change will tend to occur in whatever direction leads to a decrease in the value of the Gibbs free Energy. In this lesson we will see how G varies with thecomposition of the system as reactants change into products. When G falls as far as it can, all net change comes to a stop. The equilibrium composition of the mixture is determined by ΔG° which also defines theequilibriu Constant K. The free energy G is a quantity that becomes more negative during the course of any natural process. Thus as a chemical reaction takes place, G only falls and will never become more positive. Eventually a point is reached where any further transformation of reactants into products would cause G to increase. At this point G is at a minimum (see the plot below), and no further net change can take place; the reaction is at equilibrium.

Chemical activity

Activity is a measure of the effective concentration of a species under non-ideal (e.g., concentrated) conditions. This determines the real chemical potential for a real solution rather than an ideal one.

Activities and concentrations can both be used to calculate equilibrium constants and reaction rates. However, most of the time we use concentration even though activity is also a measure of composition, similar to concentration. It is satisfactory to use concentration for diluted solutions, but when you are dealing with more concentrated solutions, the difference in the observed concentration and the calculated concentration in equilibrium increases. This is the reason that the activity was initially created.

where • • • • •

a=Activity μ is chemical potential (dependent on standard state) which is μ0 is the standard chemical potential R is the gas constant T is the absolute Temperature