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Chemical Equilibrium

Chemical Equilibrium is the state in which the forward rate of a reaction equals its reverse rate of reaction. At the beginning of a reaction, the forward rate of reaction is higher because there are more reactants to turn into products. Over time, the products accumulate and turn back into the reactants. When the net change of reactants and products becomes zero, this is the chemical equilibrium. A chemical equilibrium can be represented by an equilibrium constant. An equilibrium can be said to be on “the far right” if most of the reactants are consumed to form the products. On the other hand, an equilibrium can be said to be on “the far left” if the most of the reactants, stay as reactants, and very little product is formed. For example, if the chemical equation is: aA + bB <--> cC + dD Then, A and B represent the reactant concentrations, while C and D represent the product concentrations. a, b, c and d represent the stoichiometric coefficients of the respective reactant and products. With this information, the equilibrium constant Kc can be written as: Kc = [C]^c [D]^d / [A]^a [B]^b The value of Kc can then be used to understand the nature of the chemical equilibrium. A high Kc value would correspond to an equilibrium on “the far right,” while a low Kc value would correspond to an equilibrium on “the far left.” Thus, studying the laws of chemical equilibrium can help predict the direction of a chemical reaction, as well as the quantity change of reactants and products as the reaction proceeds.

Categories within Chemical Equilibrium

Le Chatelier’s Principle

Postings: 23

Le Chatelier’s Principle can be used to predict how a change in condition affects a chemical equilibrium.

Blood and hemoglobin

Essay Topic: (Virtual Lab report) Life at high altitudes and haemoglobin production. More details about tasks is attached in document below: Length: 750 words (calculations are not included in the word limit) Topic: Virtual Lab Report requirements: - A minimum of 5 references. These can include journals, books, reput

Equilibrium Constant Expression

Given the following reaction: C0(g) + H2O(g) <> C02(g) + H2(g) (Please see the attachment for the properly formatted reaction). a) Write the equilibrium constant expression for this reaction. Note: gaseous-phase H20 is included in the equilibrium expressions, unlike liquid phase H20. b) The equilibrium constant for the reactio

Cell Reactions & Gases

Question #1 The gas reaction N2(g) + 3H2(g) <--> 2NH3 (g) has K- = 0.80 at 600 K and Kp = 0.15 at 650 K a) Is delta H greater than or less than zero? b) Is the reaction exothermic or endothermic? Question #2 The reaction N2 (g) + 3H2 (g) <---> 2HN3 (g) is at equlibrium a) The number of moles N2 present plus he numb

Equilibrium Reaction of Insoluble Water

Lead(II) carbonate is very insoluble in water, meaning that the equilibrium constant for the dissociation reaction is much less than 1: PbCO_3 (s) <-> Pb(2+) (aq) + CO_3(2-) (aq) Write reactions for each of the following and explain how the equilibrium reaction for the dissociation of lead(II) carbonate is affected. a.

Distribution Coefficient Question

When an aqueous solution of an organic compound is shaken with an immiscible organic solvent, such as diethyl ether, the solute distributes itself between the two phases. When the two phases separate into two distinct layers, an equilibrium will have been established such that the ratio of the concentrations of the solute in eac

Chemical Kinetics, Chemical Equilibrium & Acids and Bases

1. The following data were collected for the rate of disappearance of NO in the reaction 2NO(g)+O2(g)-----> 2NO2(g) Experiment [NO](M) [O2](M) Initial Rate(M/s) 1 0.0126 0.0125 1.41 x 10^-2 2 0.0252 0.0250 1.13 x 10^-1 3 0.0252 0.0125 5.64 x 10^-2 a

Equilibrium Constants and Precipitation

108. Consider a solution that is .022M in Fe2+ and .014M in Mg2+ a. if potassium carbonate is used to selectively precipitate one of the cations while leaving the other cation in solution, which cation will precipitate first? What minimum concentration of K2CO3 is required to cause the precipitation of the cation that precipita

Equilibrium Constant and LeChatelier's Principle

1, Calculate Ke for the following (equilibrium concentrations given below substances) a) PCl5 (g) + heat &#8596; PCl3 (g) + Cl2 (g) [0.105] [0.219] [0.219] b) 2 SO2 (g) + O2 (g) &#8596; 2 SO3 (g) + heat [0.0500] [0.0500] 0.103] c) CO2 (g) +

Equilibrium Constants and LeChatelier's Principle

1. For a certain chemical reaction, &#61508;H&#61616;= -156 kJ. Assuming the reaction is at equilibrium, classify each of the following actions by whether it causes a leftward shift, a rightward shift, or no shift in the direction of the net reaction. a. a decrease in temperature R L no shift b. an increase in tempera

Finding Equilibrium Constant and Delta G

Part 1: Ammonia can be produced by the reaction of hydrogen gas and nitrogen gas, as shown below: N2(g) + 3H2(g) &#8594; 2NH3(g) Given that the standard free energy of formation (&#8710;Gof) of NH3 (g) is -111 kJ/mol at 335 K, calculate the equilibrium constant, K, at this temperature. To express an answer in exponential

LeChatelier's Principle, Equilbrium and Combined Gas Law

Calculate Keq for the following (equilibrium concentrations given below substances) a) 2 O3 (g) &#8596; 3 O2 (g) + heat [6.0 x 10-1] [0.21] b) 2 CO2 (g) + heat &#8596; 2 CO (g) + O2 (g) [0.103] [0.024] [1.18 x 10-2] c) NO2 (g) + O2 (g) +

Equilibrium of Liquid and Boiling Point ...

Answer and explain 1)As the attractive forces between the molecules of a liquid increase, its equilibrium vapor pressure? A)increases B)decreases c)Remains the same 2)At which external pressure will water boil at the highest temp? A) 0.5 B) 1.0 C) 1.5 D) 2.0

Establishing Equilibrium

At a very high temperature, Kc = 1.0 x 10-13 for the following reaction: 2 HF(g) ---> H2(g) + F2(g) At a certain time, the following concentrations were detected. Is the system at equilibrium? If not, what must occur for equilibrium to be established? [HF] = 0.300 M, [H2] = 1.00 x 10-4 M, and [F2] = 4.00 x 10-5 M. a.

Equilibrium, Kc and Reaction Concentrations

Question 14 The equilibrium constant (Kc) for the gas phase reaction 2 NH3 --> N2 + 3 H2 is 3.0 x 10-3 at some temperature. The reaction is started by placing a 0.040-mol sample of ammonia in an empty one-liter flask. When equilibrium is established how much N2 is present? a.) 0.010 mol b.) 0.013 mol c.) 0.016 mol

Decomposition Reaction: C5H6O3(g) = C2H6(g) + 3 CO(g)

Consider the following Decomposition Reaction: C5H6O3(g) = C2H6(g) + 3 CO(g) When a 5.63g sample of pure C5H6O3(g) was sealed into an otherwise empty 2.50L flask and heated to 200C, the pressure in the flask gradually rose to 1.63 atm and remained at that value. Calculate K for this reaction.

Equilibrium Expressions Involving Acids and Bases

HOBr(aq) ----> H+(aq) + OBr-(aq) Ka = 2.3 x 10-9 1. Hydrobromous acid, HOBr, is a weak acid that disassociates in water, as represented by the equation above. (a) Calculate the value of [H+] in a HOBr solution that has pH of 4.95. (b) Write the equilibrium constant expression for the ionization of the HOBr in water,

Calculating the Equilibrium Constant for Reaction

If the following data is "true": H3PO4(aq)<--> H^+(aq) + H2PO4^-(aq) ...... .Ka1 = 7.5x10^-3 H2PO4^-(aq)<--> H+(aq) + HPO4^-2(aq) .............Ka2 = 6.2x10^-8 HPO4^-2(aq) <--> H+(aq) + HPO4^-3(aq) ............Ka3 = 4.8x10^-13 What is Ka for the reaction H3PO4(aq) <--> 3H^+(aq) + PO4^-3(aq)?

Silver Chromate Solubility and Precipitation

Answer the Questions based on Ag2CrO4 (Silver Chromate) and Ag3PO4 . Silver Chromate dissociates in water according to the equation. Ag2CrO(s)<->2Ag+ CrO4 Ksp= 2.6x10^-12 at 25 deg C. a) Write the equilibrium constant expression for Ag2CrO4 (Silver Chromate) b) Calculate the concentration, in mol L-1 of Ag in a saturated so

Computing the Equilibrium Constant of a Reaction

Consider the equilibrium: 3A <----> B You prepare a mixture with initial concentrations [A]0 = 0.61 mol/L, and [B]0 = 0. You wait until the mixture reaches equilibrium, and then you measure the concentration of B: [B]eq = 0.11 mol/L. From your experiment compute the equilibrium constant Kc of the reaction.

Relating to the solubilities of two silver compounds

Answer the following questions relating to the solubilities of two silver compounds. Ag2CrO4 and Ag3PO4 Silver chronate dissociates in water according to the equation shown below Ag2CrO4 (s). = 2 Ag+ (aq) + CrO4 2- (aq) Ksp = 2.6 x 10^-12 at 25C A) write the equilibrium constant expression for the dissolving of Ag

Equilibrium: solubility

Answer the following questions that relate to solubility of salts of lead and barium: A) A saturated solution is prepared by adding excess PbI2(s) to distilled water to form 1.0 L of solution at 25C. The concentrations of Pb2+ (aq) in the saturated solution is found to be 1.3 x 10^-3 M. The chemical equation for the dissoluti

Chemical Equilibrium: Constants, Temperature, Concentrations

1. Describe the equilibrium constant in terms of the law of mass action and write equilibrium constant expression for multiple equilibria. 2. Relate the constants and equilibrium constants and describe how equilibrium varies with temperature. 3. Use equilibrium constants to predict the direction of a reaction towards equil

Concentration after Equilibrium

Consider the equilibrium A <----> B. The equilibrium constant is Kc = 0.909, and the initial concentrations are [A]0 = 0.17 mol/L and [B]0 = 0 mol/L. Compute [A] after equilibrium has been reached. (in mol/L) (Using correct significant figures.)

Equilibrium Value

In the reaction CO(g) + Cl2(g)<---> COCl2(g), Kc = 1200 at 395 K. What is the equilibrium value of [COCl2] if at equilibrium, [CO] = 2[Cl2] = 1/2[COCl2]? (in M) (Use correct significant figures.)

equilibrium constant, Kc

If the equilibrium concentrations found in the reaction 2 A(g) + B(g) <----> C(g) are [A] = 0.024 M, [B] = 0.0046 M, and [C] = 0.0062 M, calculate the value of Kc.


In the following reaction N2O4(g) <-----> 2 NO2(g), equilibrium is reached at a temperature at which partial pressure of NO2 P_NO2 = 3(P(of)N2O4)^1/2. What must be the value of equilibrium constant Kp at this temperature?

Equilibrium Value of a Gas Reaction

In the reaction 2H2(g) + S2(g) <-----> 2H2S(g), K(subscript)c = 6.28 x 10^3 at 900 K. What is the equilibrium value of [H2] if at equilibrium [H2S] = [S2]^(1/2)? (in M)