K\)). Calculate the average molar mass (in gm/mol)of an equilibrium mixture. Important Questions on Applications Of Equilibrium Constants is available on Toppr. Have questions or comments? One idea: a patient lying in bed is in static equilibrium (static because he is not moving). If Kc is very large, the reaction proceeds almost all the way to completion. Applications of the Principles of Chemical Equilibrium to Reactions of Industrial Importance. Figure $$\PageIndex{4}$$: The Concentration of $$NH_{3(g)}$$ versus the Concentration of $$HI_{(g)}$$ for system in Reaction \ref{15.6.5} at Equilibrium. Applications of Equilibrium Constants. As a result, for a given concentration of either $$\ce{HI}$$ or $$\ce{NH_3}$$, only a single equilibrium composition that contains equal concentrations of both $$\ce{NH_3}$$ and $$\ce{HI}$$ is possible, for which, $[\ce{NH_3}] = [\ce{HI}] = \sqrt{K}. for which $$K = 4.65 \times 10^{−3}$$ at 298 K. We can write $$Q$$ for this reaction as follows: \[Q=\dfrac{[\ce{NO2}]^2}{[\ce{N2O4}]} \label{15.6.2}$. It may be noted that Q becomes equal to equilibrium constant (K) when the reaction is at the equilibrium state. For example, point A in Figure $$\PageIndex{3}$$ lies below the line, indicating that the $$[\ce{H_2O}]/[\ce{H_2}]$$ ratio is less than the ratio of an equilibrium mixture (i.e., $$Q < K$$). In this section, we describe how to quantitatively analyze the composition of a reaction mixture to make this determination. Applications of Equilibrium Constant (1) Judging the extent of reaction (i) If K c > 10 3, products predominate over reactants.If K c is very large, the reaction proceeds almost all the way to completion. Application of EquilibriumBy: Stephanie, Shawna, and Amber 2. | Find, read and cite all the research you need on ResearchGate Example Definitions Formulaes. \nonumber\]. Register & Get Sample Papers solutions instantly. In contrast, when just enough $$\ce{PbCO_3}$$ has been added to give $$[CO_2] = K$$, the system has reached equilibrium, and adding more $$\ce{PbCO_3}$$ has no effect on the $$\ce{CO_2}$$ concentration: the graph is a horizontal line. Comparing the magnitudes of $$Q$$ and $$K$$ enables us to determine whether a reaction mixture is already at equilibrium and, if it is not, predict how its composition will change with time to reach equilibrium (i.e., whether the reaction will proceed to the right or to the left as written). R is the universal gas constant and T is the temperature. If $$Q = K$$, then the system is at equilibrium. For more information contact us at [email protected] or check out our status page at https://status.libretexts.org. Thus any $$\ce{CO_2}$$ concentration that is not on the horizontal line represents a nonequilibrium state, and the system will adjust its composition to achieve equilibrium, provided enough $$\ce{PbCO_3}$$ and $$\ce{PbO}$$ are present. 20,000+ Learning videos. In explaining the principles and application of the Haber process and equilibrium constant, we must first understand that there is a relationship between these two above mentioned concepts and two other concepts known as free energy and electrode potential. Applications of Equilibrium Constant: Predicts the extent of reaction, which gives the degree of the disappearance of reactants. Compare $$Q$$ and $$K$$ to determine in which direction the reaction will proceed. concentration of products is much larger than that of […] All forces on the object balance out. (2) Predicting the direction of reaction: The concentration ratio, i.e., ratio of the product of concentrations of products to that of reactants is also known as concentration quotient and is denoted by Q. Equilibrium Constant and Reaction Quotient. Such a graph allows us to predict what will happen to a reaction when conditions change so that $$Q$$ no longer equals $$K$$, such as when a reactant concentration or a product concentration is increased or decreased. If $$[\ce{H_2O}]$$ is doubled at equilibrium, then $$[\ce{H2}]$$ must also be doubled for the system to remain at equilibrium. Disposable Camera Developing, How To Reduce The Cost Of Feeding Tilapia, Indomie Noodles Calories Without Oil, Powerpoint 2019 Pdf, Horse Property For Sale San Diego, Captions For Beautiful Pictures, One Story Houses For Sale Near Me, Microsoft Office 2019 Tutorial Pdf, Cascade Yarn Ontario, Hand And Stone Chicago Lakeview, High Femme Cerise Rooftop, "/>

# applications of equilibrium

Given: balanced chemical equation, $$K$$, amounts of reactants and products, and volume, A We must first find the initial concentrations of the substances present. Applications of the Principles of Chemical Equilibrium to Reactions of Industrial Importance. Again, only those pairs of concentrations of $$\ce{H_2O}$$ and $$\ce{H_2}$$ that lie on the line correspond to equilibrium states. In contrast, the reduction of cadmium oxide by hydrogen gives metallic cadmium and water vapor: $\ce{CdO(s) + H2(g) <=> Cd(s) + H_2O(g)} \label{15.6.4}$. In the water–gas shift reaction introduced in Example $$\PageIndex{1}$$, carbon monoxide produced by steam-reforming reaction of methane reacts with steam at elevated temperatures to produce more hydrogen: $\ce{CO(g) + H_2O(g) <=> CO2(g) + H2(g)} \nonumber$. Le-Chatelier’s principle of equilibrium is used in the industrial applications as the reaction scheme involves parameters like temperature, pressure, concentration of reaction species a change in even single parameter results in the change of equilibrium leads to undesired product formation. In whatever context it is used, it almost always refers to balance. We show that this problem can be solved by the inexact proximal point method if there exists a solution to the dual problem. This particular word is used extensively in the realms of physics as well as biology, chemistry and economics etc. Points that do not lie on the line or curve represent nonequilibrium states, and the system will adjust, if it can, to achieve equilibrium. The application of limit equilibrium analysis and numerical simulation in case of slope instability is described. An application of this approach to … Any point that lies below and to the left of the equilibrium curve (such as point A in Figure $$\PageIndex{4}$$) corresponds to $$Q < K$$, and the reaction in Equation $$\ref{15.6.5}$$ will therefore proceed to the right as written, causing the composition of the system to move toward the equilibrium line. Graphs derived by plotting a few equilibrium concentrations for a system at a given temperature and pressure can be used to predict the direction in which a reaction will proceed. If $$Q < K$$, the reaction will proceed to the right as written. Thus the left portion of the graph represents a system that is not at equilibrium because it contains only $$\ce{CO2(g)}$$ and $$\ce{PbO(s)}$$. To predict in which direction a reaction will proceed. Equilibrium is one of the most common and perhaps well-known aspects of economics, both in micro and macro applications.The applications of microeconomics look at equilibrium on a per-product level rather than an entire market level in most cases. Reaction Quotient (Q): There are also various ways to state the zeroth law of thermodynamics. (ii) If K c > 10 3, reactants predominate over products.If K c is very small, the reaction proceeds hardly at all. the concentration of products is much larger than that of the reactants at equilibrium.For Example: 1. Learn with Videos. Calculations Involving Equilibrium Constant. So think of something that is not accelerating (not so easy if it must involve nursing). (ii) If Kc > 103, reactants predominate over products. Industrial Applications. The reaction Quotient ($$Q$$) is used to determine whether a system is at equilibrium and if it is not, to predict the direction of reaction. If $$Q > K$$, the reaction will proceed to the left as written. The law is based on temperature measurement. All rights reserved. By graphing a few equilibrium concentrations for a system at a given temperature and pressure, we can readily see the range of reactant and product concentrations that correspond to equilibrium conditions, for which $$Q = K$$. Initially, the added $$\ce{PbCO_3}$$ decomposes completely to $$\ce{CO_2}$$ because the amount of $$\ce{PbCO_3}$$ is not sufficient to give a $$\ce{CO_2}$$ concentration equal to $$K$$. Applications include models from mathematical economics, Nash equilibrium of non-cooperative games, and Browder variational inclusions. EATING SUGAR AND TOOTH DECAY STEPHANIE LEHSTEN 3. Reaction Quotient (Q): We consider a general equilibrium problem defined on a convex set, whose cost bifunction may not be monotone. Class 11 Medical - Applications of Equilibrium Constants Class 11 Engineering - Applications of Equilibrium Constants. By graphing equilibrium concentrations for a given system at a given temperature and pressure, we can predict the direction of reaction of that mixture when the system is not at equilibrium. The purpose of the study was to use both limit equilibrium methods (LEMs) and numerical simulations (finite element method (FEM)) to understanding the common factor imposing the selected slope into slope instabilities. The reaction will therefore proceed to the right as written, forming $$\ce{H2}$$ and $$\ce{CO}$$ at the expense of $$\ce{H_2O}$$ and $$\ce{CH4}$$. Equilibrium and Center of Gravity in Real Objects Before applying the concept of vector sums to matters involving equilibrium, it is first necessary to clarify the nature of equilibrium itself—what it is and what it is not. $$[\ce{CO}] = 8.0 \times 10^{−3} M$$, and. -production must ALWAYS be ECONOMIC which means produces the most product EFFICIENTLY The magnitude of the equilibrium constant gives an idea of the relative amount of the reactants and the products.Case 1: The larger value of the equilibrium constant (>103) shows that forward reaction is favored i.e. R is the universal gas constant and T is the temperature. This statement defines the zeroth law of thermodynamics. Applications of Chemcial Equilibrium in Industrial Production In Industrial Production... - Industrial Production used to produce compounds that can be harnessed and used in other applications. (i) If Kc > 103, products predominate over reactants. Application of Equilibrium Optimizer Algorithm for Optimal Power Flow with High Penetration of Renewable Energy . The following table lists data from three experiments in which samples of the reaction mixture were obtained and analyzed at equivalent time intervals, and the corresponding values of $$Q$$ were calculated for each. To reach equilibrium, the system must increase $$[\ce{CO_2}]$$, which it can do only by decomposing solid $$\ce{PbCO_3}$$ to form $$\ce{CO_2}$$ and solid $$\ce{PbO}$$. Applications of Equilibrium Constant (1) Judging the extent of reaction (i) If K c > 10 3, products predominate over reactants.If K c is very large, the reaction proceeds almost all the way to completion. Legal. Missed the LibreFest? If $$Q = K$$, for example, then the system is already at equilibrium, and, If $$Q < K$$, then the ratio of the concentrations of products to the concentrations of reactants is less than the ratio at equilibrium. A plot of $$[\ce{H_2O}]$$ versus $$[\ce{H_2}]$$ at equilibrium is a straight line with a slope of $$K$$ (Figure $$\PageIndex{3}$$). Important features and applications of the equilibrium constant are listed below - Expression for equilibrium constant is applicable only when concentrations of the reactants and products have attained constant value at equilibrium state. According to the First condition of equilibrium sum of forces acting on a body is zero ( â F =0 ), While according to the second condition of equilibrium sum of torque acting on a body is zero ( â Ï = 0 ).. What is the equilibrium in physics? Protection and Metering Department, National Electric Power Company, Amman 11181, Jordan. (ii) If Q < K, the reaction will proceed in the direction of the products (forward reaction). Application of equilibrium 1. In this lesson we discuss equilibrium, Le Chatelier's principle, changing equilibrium conditions as well as look at graph examples. industrial applications of equilibrium for AS-level chemistry The equilibrium constant K p (in atm) for the reaction is 9 at 7 atm and 300 K. A 2 (g) â B 2 (g) + C 2 (g). The content is self-contained and the book is mainly addressed to researchers in mathematics, economics and mathematical physics as well as to graduate students in applied nonlinear analysis. In this live Gr 12 Physical Sciences show we take a close look at Applications of Chemical Equilibrium. 2. We can calculate the other concentrations in a similar way: B We now compute $$Q$$ and compare it with $$K$$: \begin{align*} Q&=\dfrac{[\ce{CO}][\ce{H_2}]^3}{[\ce{CH_4}][\ce{H_2O}]} \\[4pt] &=\dfrac{(8.0 \times 10^{−3})(3.0 \times 10^{−3})^3}{(6.0\times 10^{−3})(4.0 \times 10^{−3})} \\[4pt] &=9.0 \times 10^{−6} \end{align*}. The reaction in Equation \ref{15.6.3} will therefore proceed to the right as written, until $$[\ce{CO_2}] = K$$. The content is self-contained and the book is mainly addressed to researchers in mathematics, economics and mathematical physics as well as to graduate students in applied nonlinear analysis. Therefore, the reaction will proceed to the, If $$Q > K$$, then the ratio of the concentrations of products to the concentrations of reactants is greater than at equilibrium, so the reaction will proceed to the. Calculating the equilibrium constant, which gives the relative amount of reactants and products. If Kc is very small, the reaction proceeds hardly at all. Predicts the direction of the reaction. This particular word is used extensively in the realms of physics as well as biology, chemistry and economics etc. In another example, solid ammonium iodide dissociates to gaseous ammonia and hydrogen iodide at elevated temperatures: $\ce{ NH4I(s) <=> NH3(g) + HI(g)} \label{15.6.5}$. 9 min. When a body ‘A’ is in thermal equilibrium with another body ‘b’, and also separately in thermal equilibrium with a body ‘C’, then body ‘B’ and ‘C’ will also be in thermal equilibrium with each other. Statics and Equilibrium - Real-life applications Photo by: emese73. Application of equilibrium 1. 8,000+ Fun stories. PDF | This presentation is useful to become familiar with problems about Chemical Equilibrium. APPLICATION OF EQUILIBRIUM CONSTANT : www.citycollegiate.com. $$K = 0.64$$ at 900 K. If 0.010 mol of both $$\ce{CO}$$ and $$\ce{H_2O}$$, 0.0080 mol of $$\ce{CO_2}$$, and 0.012 mol of $$\ce{H_2}$$ are injected into a 4.0 L reactor and heated to 900 K, will the reaction proceed to the left or to the right as written? Thus the reaction in Equation $$\ref{15.6.4}$$ will proceed to the left as written, consuming $$\ce{H_2O}$$ and producing $$\ce{H_2}$$, which causes the concentration ratio to move down and to the right toward the equilibrium line. An object in equilibrium has no acceleration, so it is either not moving or moving at a constant velocity. Use Equation $$\ref{15.6.1}$$ to determine $$Q$$ . (iii) If Q = K, the reaction mixture is already at equilibrium. Thus, a reaction has a tendency to form products if Q < K and to form reactants if Q > K. Notice: JavaScript is required for this content. Important features and applications of the equilibrium constant are listed below - Expression for equilibrium constant is applicable only when concentrations of the reactants and products have attained constant value at equilibrium state. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. In such cases, the reaction in Equation $$\ref{15.6.4}$$ will proceed in whichever direction causes the composition of the system to move toward the equilibrium line. what john forbes nash jr. said in his the simplicity of nash equilibrium enabled the growth of game theory as a legitimate discipline and enabled. Le-Chatelierâs principle of equilibrium is used in the industrial applications as the reaction scheme involves parameters like temperature, pressure, concentration of reaction species a change in even single parameter results in the change of equilibrium leads to undesired product formation. 2. the degree of the disappearance of the reactants. Thus the ratio of the concentrations of products to the concentrations of reactants is less than the ratio for an equilibrium mixture. To understand how information is obtained using a reaction Quotient, consider the dissociation of dinitrogen tetroxide to nitrogen dioxide. Watch the recordings here on Youtube! APPLICATIONS OF CHEMICAL EQUILIBRIUM 27 MAY 2014 Lesson Description In this lesson we: Discuss Le Chatelier’s Principle Discuss application of Le Chatelier’s Principle Summary Le Chatelier’s Principle If the equilibrium in an isolated system is disturbed by changing one of the equilibrium … Predicts the direction of the reaction. The less expensive the process the better. To reach equilibrium, the system must decrease $$[\ce{CO_2}]$$, which it can do only by reacting $$\ce{CO_2}$$ with solid $$\ce{PbO}$$ to form solid $$\ce{PbCO_3}$$. Unless otherwise noted, LibreTexts content is licensed by CC BY-NC-SA 3.0. A simple mechanical body is said to be in equilibrium if it experiences neither linear acceleration nor angular acceleration; unless it is disturbed by an outside force, it will continue in that condition indefinitely. Because $$K = 2.4 \times 10^{−4}$$, we see that $$Q < K$$. In whatever context it is used, it almost always refers to balance. It may be noted that Q becomes equal to equilibrium constant (K) when the reaction is at the equilibrium state. Applications include models from mathematical economics, Nash equilibrium of non-cooperative games, and Browder variational inclusions. The Haber process is a good example of an industrial process which uses the equilibrium principles that have been discussed. Applications include models from mathematical economics, Nash equilibrium of non-cooperative games, and Browder variational inclusions. Solve Easy, Medium, and Difficult level questions from Applications Of Equilibrium Constants $$Q = 0.96$$. Knowledge of equilibrium constant for a given reaction is very helpful aid in laboratory analysis as well as in industry. In explaining the principles and application of the Haber process and equilibrium constant, we must first understand that there is a relationship between these two above mentioned concepts and two other concepts known as free energy and electrode potential. (i) If Q > K, the reaction will proceed in the direction of reactants (reverse reaction). The Wikipedia defines equilibrium as the condition of a system in which competing influences are balanced. Equilibrium, in physics, the condition of a system when neither its state of motion nor its internal energy state tends to change with time. The applications of microeconomics look at equilibrium on a per-product level rather than an entire market level in most cases. Price is the most important factor in supply-and-demand equilibrium, so any internal factor that affects the cost of goods can affect price and equilibrium â¦ We previously saw that knowing the magnitude of the equilibrium constant under a given set of conditions allows chemists to predict the extent of a reaction. For this system, $$K$$ is equal to the product of the concentrations of the two products: If we double the concentration of $$\ce{NH3}$$, the concentration of $$\ce{HI}$$ must decrease by approximately a factor of 2 to maintain equilibrium, as shown in Figure $$\PageIndex{4}$$. by Khaled Nusair. When a reaction system is at equilibrium, $$Q = K$$. Lead carbonate decomposes to lead oxide and carbon dioxide according to the following equation: $\ce{PbCO3(s) <=> PbO(s) + CO2(g)} \label{15.6.3}$, Because $$\ce{PbCO_3}$$ and $$\ce{PbO}$$ are solids, the equilibrium constant is simply. Therefore, for the following general reaction: the reaction quotient is defined as follows: $Q=\dfrac{[C]^c[D]^d}{[A]^a[B]^b} \label{15.6.1}$. This phenomenon helps us in carrying out our… At a given temperature, therefore, any system that contains solid $$\ce{PbCO_3}$$ and solid $$\ce{PbO}$$ will have exactly the same concentration of $$\ce{CO_2}$$ at equilibrium, regardless of the ratio or the amounts of the solids present. This situation is represented in Figure $$\PageIndex{3}$$, which shows a plot of $$[\ce{CO_2}]$$ versus the amount of $$\ce{PbCO_3}$$ added. However, in simple terms, it can be said, “Systems that are in ther… Conversely, the point labeled B in Figure $$\PageIndex{2}$$ lies below the horizontal line, so it corresponds to a $$[\ce{CO_2}]$$ that is less than the equilibrium concentration of $$\ce{CO_2}$$ (i.e., $$Q < K$$). In industrial processes the primary objective is to maximize the yield of products at a minimum cost in a shorter period of time. Thus the reaction in Equation $$\ref{15.6.3}$$ will proceed to the left as written, until $$[\ce{CO_2}] = K$$. Save teachers time and engage students with a new, simpler interface! If $$1.2 \times 10^{−2}$$ mol of $$CH_4$$, 8.0 × 10−3 mol of $$H_2O$$, $$1.6 \times 10^{−2}$$ mol of $$CO$$, and $$6.0 \times 10^{−3}$$ mol of $$H_2$$ are placed in a 2.0 L steel reactor and heated to 900 K, will the reaction be at equilibrium or will it proceed to the right to produce $$\ce{CO}$$ and $$\ce{H_2}$$ or to the left to form $$\ce{CH_4}$$ and $$\ce{H_2O}$$? By graphing equilibrium concentrations for a given system at a given temperature and pressure, we can predict the direction of reaction of that mixture when the system is not at equilibrium. Application of Equilibrium constant 1) Predicting the extent of reaction The magnitude of the equilibrium constant gives an idea of the relative amount of the reactants and the products. In industrial processes the primary objective is to maximize the yield of products at a minimum cost in a shorter period of time. $$K = 2.4 \times 10^{−4}$$ at 900 K. Huge amounts of hydrogen are produced from natural gas in this way and are then used for the industrial synthesis of ammonia. (iii) If Kc is in the range 103 to 103, appreaciable concentration of both reactants and products are present. Any point representing a pair of concentrations that does not lie on the line corresponds to a nonequilibrium state. In industrial processes, it is important to get the product as quickly and as efficiently as possible. Since (Q > K), so the reaction will proceed to the left, and $$CO$$ and $$H_2O$$ will form. 15.6: Applications of Equilibrium Constants, [ "article:topic", "reaction quotient", "showtoc:no", "license:ccbyncsa" ], Predicting the Direction of a Reaction with a Graph, $$\dfrac{(0.0600)^2}{0}=\text{undefined}$$, $$\dfrac{(0.0200)^2}{0.0600}=6.67 \times 10^{−3}$$. Conversely, point B in Figure $$\PageIndex{3}$$ lies above the line, indicating that the $$[\ce{H_2O}]/[\ce{H_2}]$$ ratio is greater than the ratio of an equilibrium mixture ($$Q > K$$). Calculate the average molar mass (in gm/mol)of an equilibrium mixture. Important Questions on Applications Of Equilibrium Constants is available on Toppr. Have questions or comments? One idea: a patient lying in bed is in static equilibrium (static because he is not moving). If Kc is very large, the reaction proceeds almost all the way to completion. Applications of the Principles of Chemical Equilibrium to Reactions of Industrial Importance. Figure $$\PageIndex{4}$$: The Concentration of $$NH_{3(g)}$$ versus the Concentration of $$HI_{(g)}$$ for system in Reaction \ref{15.6.5} at Equilibrium. Applications of Equilibrium Constants. As a result, for a given concentration of either $$\ce{HI}$$ or $$\ce{NH_3}$$, only a single equilibrium composition that contains equal concentrations of both $$\ce{NH_3}$$ and $$\ce{HI}$$ is possible, for which, $[\ce{NH_3}] = [\ce{HI}] = \sqrt{K}. for which $$K = 4.65 \times 10^{−3}$$ at 298 K. We can write $$Q$$ for this reaction as follows: \[Q=\dfrac{[\ce{NO2}]^2}{[\ce{N2O4}]} \label{15.6.2}$. It may be noted that Q becomes equal to equilibrium constant (K) when the reaction is at the equilibrium state. For example, point A in Figure $$\PageIndex{3}$$ lies below the line, indicating that the $$[\ce{H_2O}]/[\ce{H_2}]$$ ratio is less than the ratio of an equilibrium mixture (i.e., $$Q < K$$). In this section, we describe how to quantitatively analyze the composition of a reaction mixture to make this determination. Applications of Equilibrium Constant (1) Judging the extent of reaction (i) If K c > 10 3, products predominate over reactants.If K c is very large, the reaction proceeds almost all the way to completion. Application of EquilibriumBy: Stephanie, Shawna, and Amber 2. | Find, read and cite all the research you need on ResearchGate Example Definitions Formulaes. \nonumber\]. Register & Get Sample Papers solutions instantly. In contrast, when just enough $$\ce{PbCO_3}$$ has been added to give $$[CO_2] = K$$, the system has reached equilibrium, and adding more $$\ce{PbCO_3}$$ has no effect on the $$\ce{CO_2}$$ concentration: the graph is a horizontal line. Comparing the magnitudes of $$Q$$ and $$K$$ enables us to determine whether a reaction mixture is already at equilibrium and, if it is not, predict how its composition will change with time to reach equilibrium (i.e., whether the reaction will proceed to the right or to the left as written). R is the universal gas constant and T is the temperature. If $$Q = K$$, then the system is at equilibrium. For more information contact us at [email protected] or check out our status page at https://status.libretexts.org. Thus any $$\ce{CO_2}$$ concentration that is not on the horizontal line represents a nonequilibrium state, and the system will adjust its composition to achieve equilibrium, provided enough $$\ce{PbCO_3}$$ and $$\ce{PbO}$$ are present. 20,000+ Learning videos. In explaining the principles and application of the Haber process and equilibrium constant, we must first understand that there is a relationship between these two above mentioned concepts and two other concepts known as free energy and electrode potential. Applications of Equilibrium Constant: Predicts the extent of reaction, which gives the degree of the disappearance of reactants. Compare $$Q$$ and $$K$$ to determine in which direction the reaction will proceed. concentration of products is much larger than that of […] All forces on the object balance out. (2) Predicting the direction of reaction: The concentration ratio, i.e., ratio of the product of concentrations of products to that of reactants is also known as concentration quotient and is denoted by Q. Equilibrium Constant and Reaction Quotient. Such a graph allows us to predict what will happen to a reaction when conditions change so that $$Q$$ no longer equals $$K$$, such as when a reactant concentration or a product concentration is increased or decreased. If $$[\ce{H_2O}]$$ is doubled at equilibrium, then $$[\ce{H2}]$$ must also be doubled for the system to remain at equilibrium.