Reversible reaction and dynamic equilibrium 10th class. Chemical equilibrium deals with to what extent a chemical reaction proceeds. Generic, then real but simple numbers p8 writing the equilibrium constant p3 solving for k given initial and at least one equilibrium concentration p9 manipulations of k. Reactions reach chemical equilibrium when the rate of the forward reaction equals the rate of the reverse reaction. They were revised by konstantinos serfes in 1997, by melike bulu in 1998, and by deukwon kim in 2003. Chemical reactions reach a state of dynamic equilibrium in which the rates of forward and reverse reactions are equal and there is no net. Chemical equilibrium ii 1 equilibrium calculations common manipulation. We start to consider how external factors can push the equilibrium in one direction or the other. Given a chemical equation, write the law of mass action. Manipulate the equilibrium constant to reflect changes in the chemical equation. General chemistry ii chapter 14 lecture notes chemical equilibrium. Lecture 2 adiabatic flame temperature and chemical equilibrium.
Chemical equilibrium and complete combustion are valid in the limit of infinitely fast reaction rates only, which will seldom be valid in combustion systems. In this lecture, we discuss the nature of chemical equilibrium and of the chemical equilibrium constant. If at equilibrium the concentration of one of the reactants is increased. When a chemical reaction has reached the equilibrium state, the concentrations of reactants and products remain constant over time, and there are no visible. Ninth grade lesson introduction to chemical equilibrium. But you probably dont have a really good intuition as to why it is what it is. Monday, february 19, 2001 page 1 of 4 lecture notes l. Refine the design of a chemical system by specifying a change in conditions that. I hope you will see just how easily equilibrium concepts can be applied to. Write the equilibriumconstant expression for a heterogeneous reaction. The concept of chemical equilibrium which we treat in this chapter addresses this question directly.
Given the equilibrium constant k eq for a reaction, predict whether the reactants or products are predominant. Reactions proceed forward and backward, and these opposing processes reach a state of equilibrium based on many conditions. This leads to the idea of a dynamic equilibrium, and what the common term position of equilibrium means. Yannelis department of economics university of illinois, urbanachampaign august 2003 1the notes, based on my lectures, were. It talks about reversible reactions and how they behave if the system is closed. Optimisation of the operational conditions is very important in industry and laboratory so that equilibrium is favorable in the direction of the desired product. Kenneth denbigh the principles of chemical equilibrium cambridge university press 1957 acrobat 7 pdf 23. North carolina school of science and mathematics 75,937 views. Equilibrium in reversible reaction the graph depicts that the rate of forward reaction gradually decreases while the rate of backward reaction increase till they become constant and equal to. Chemistry 12 unit 2 notes equilibrium unit 2 notes equilibrium page 2 once this has happened for awhile, there is a build up of no2 molecules in the same flask once in awhile, two no2 molecules will collide with each other and join to form a molecule of n2o4. Chromate dichromate ion equilibrium lechateliers principle lab part 2 duration. Introduction to chemical equilibrium this lecture is outside the confines of the textbook development of chemical equilibrium and is intended as a sweeping introduction to chemical equilibrium a topic that will engage us for much the rest of the semester. Le chateliers principle states that if a system at equilibrium is subjected to a change in concentration.
The reaction will proceed at a certain rate fast or slow, and the rate at which the. In this dynamic process, the forward and reverse reactions proceed at the. Lecture 9 chemical equilibrium and solution chemistry why do we need to study chemical equilibrium. The extent of a reaction in equilibrium varies with the experimental conditions such as concentrations of reactants, temperature, etc. Unit 8 nel chemical equilibrium focusing on acidbase systems 673 4. An introduction chemical equilibrium a dynamic state in which the rate of the forward reaction and the rate of the reverse reaction in a system are equal the concentration of the products and reactants. Those that need some refreshing on their inorganic chemistry should open a chemistry textbook. Exchange varian, intermediate microeconomics introduction we have only studied the demand for a single good, and from the introduction course we know that the interaction of the market demand curve for a particular good what we have analyzed in detail in this course and the supply function determines the equilibrium. The material in this lecture comes from the field of chemical thermodynamics. Lecture 12 free download as powerpoint presentation.
The concept of equilibrium chemical equilibrium occurs when a reaction and its reverse reaction proceed at the same rate. Pdf many chemical reactions can under the proper conditions be made to go predominantly in one direction or the other. I hope you will see just how easily equilibrium concepts can be. The reaction proceeds to certain extent and reaches a state at which the concentrations of both reactants and products remain constant with time. Reaction quotient, q, and criteria for spontaneity. Friday, february 25, 2005 page 1 of 4 lecture notes k. In a later chapter we will see that the tendency of a reaction to occur can be predicted entirely from the properties of the reactants and products through the law of thermodynamics.
Find materials for this course in the pages linked along the left. Many chemical reactions can, under the proper conditions, be made to go predominantly in one direction or. A value called the equilibrium constant can be assigned to the chemical system by measuring, at equilibrium, the concentrations of all the species. We will consider finite rate chemical kinetics in a later lecture. So the point of the class here is not to relearn log k is equal to minus delta g, reaction divided by rt. Reaction rates are related to chemical equilibrium because a chemical system is at equilibrium when the rate of the forward reaction equals the rate of the reverse reaction. Chapter 15 chemical equilibrium the concept of equilibrium. Unit 8 chemical equilibrium focusing on acidbase systems. The state where the concentrations of all reactants and products remain constant with time 2. Many chemical reactions do not go to completion but instead attain a state of chemical equilibrium. Chemical equilibrium iv 1 partial pressures you have a 1. Introduction introduction when a liquid evaporates in a closed container molecules with relatively higher kinetic energy escape the liquid surface into the vapour phase strike the liquid surface and are retained in the liquid phase. Obtaining the equilibrium constant for a reaction equilibrium concentrations for a reaction must be determined experimentally and then substituted into the equilibriumconstant expression in order to calculate k c.
Lecture 8 ram singh course 001 october 1, 2014 ram singh. All right, so chemical reactions, chemical reactions can go into a state of equilibrium. And its a dynamic equilibrium, the reaction is still happening, but if a reaction is an equilibrium, the rate of the forward reaction will equal the rate of the reverse reaction, so therell be no net change in composition. All reactions carried out in a closed vessel will reach equilibrium a. Class 11 chemistry revision notes for chapter 7 equilibrium. Use le chateliers principle to explain how a chemical reaction at equilibrium responds when a change is made to the concentration of reactant or.
Monday, february 21, 2005 page 2 of 11 concept consider the reaction. In fact, we will spend much of the rest of the course discussing aspects of this concept. Chemical equilibrium is the type of dynamic equilibrium that involves chemical reactions. Reversing or multiplying p5 solving for equilibrium concentrations using ice, given k p10. Lecture notes in general equilibrium theory 1 by nicholas c. Unit 5 chemical kinetics and equillibrium notes answers.
Entire books and courses at the undergraduate and graduate level are devoted to them. C or d c o n c e n t r a t i o n time a or b equilibrium fig. The concentration of chemical substances in solution can vary widely figure 2. Lecture 9 chemical equilibrium and solution chemistry. Concentration affects solution properties such as colour, conductivity, freezing point, and viscosity. Thus, rg m rt lnk for a given reaction, k is a number that depends only on the. I will use to indicate an equilibrium process in my lecture notes. This process, as you might have guessed is indicated by the reverse reaction. A chemical equilibrium refers to the balance of two competitive reactions forward and reverse in a reversible reaction. If little product is formed, equilibrium lies far to the left b. Notes for chemical equilibrium thermodynamics chemical equilibrium understanding how to work problems for chemical equilibrium is one of the most important concepts in secondsemester chemistry. Chemical kinetics the study of the rates of chemical processes. Equilibrium constant k, log delta g of the reaction, et cetera, et cetera. Dse general equilibrium analysis october 1, 2014 1 16.
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