Chemical equilibrium Definition and 78 Threads

In a chemical reaction, chemical equilibrium is the state in which both the reactants and products are present in concentrations which have no further tendency to change with time, so that there is no observable change in the properties of the system. This state results when the forward reaction proceeds at the same rate as the reverse reaction. The reaction rates of the forward and backward reactions are generally not zero, but they are equal. Thus, there are no net changes in the concentrations of the reactants and products. Such a state is known as dynamic equilibrium.

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  1. K

    Chemical Equilibrium with individual reactions

    Homework Statement Homework Equations Kc = (Kp)/ (RT)delta n K_c = (K_a)(K_b) (Where a and b are the individual reactions while c is the overall reaction where the coefficients are the same) The Attempt at a Solution The question prior to this one has individual reactions as...
  2. P

    Doubt in chemical equilibrium question.

    Homework Statement For the chemical equilibrium N_{2(g)} + O_{2(g)} \rightleftharpoons 2NO_{(g)} , the following values were found for the constant Kc (chemical equilibrium constant), at the indicated temperatures: (The table is attached as an image) Table in text format: Temperature (K)...
  3. A

    Chemical equilibrium system and where my ions went

    sorry if this has been asked before, i did a search and couldn't find any results. Explain fully what happens when H^+ is added to a mixture containing BaCrO_4(s) and CrO_4^2^-. The overall equation of ions in this experiment is...
  4. L

    Explaining the Effects of Removing UO2 on a Chemical Equilibrium

    Homework Statement Suppose the reaction system UO2(s) +4HF(g) <-> UF4(g) +2H2O(l) is sealed in a container and allowed to equilibrate at a particular temperature. Explain what happens to the nature of each substance if you: a. remove some UO2 from the system b. remove all UO2 from the...
  5. A

    How Do You Calculate the Solubility of PbI2 in .300m AlI3?

    Homework Statement Hey all, I'm new here, so hello to all of you. Question: "Calculate the solubility of PbI2 in .300m AlI3 (PbI2 - Ksp = 2.0x10-30)" So I'm not really sure how to do the symbols and such, but that's a try. Now I'm seeing it two ways. One: Right a disassociation equation as...
  6. A

    Chemical Equilibrium: Calculating K with Ideal Gas Law

    Homework Statement It is a chem equilibrium question, involving the ICE table. The following reaction: S2(g) + 2H2 (g) ←→ 2SH2(g) takes place at high temperatures. If the initial amount of H2 and SH2 is 1.75 g and 1.95 g, respectively, and at equilibrium the amount of S2(g) is found to be...
  7. L

    Chemical Equilibrium: Observing Changes in Cr2O7- & CrO4- Mixture

    an equilibrium exists between chromate ion and the dichromate ion when potassium chromate is dissolved acid. the net ionic equation describing this reaction is given in the follwering equation: 2 CrO4^2- (aq) + 2 H3O^+ (equilibrium symbol) Cr2O7^2- (aq) + 3 H2O (l) a student studying this...
  8. R

    Calculating Mole Fraction and Kp in Chemical Equilibrium

    Chemical equilibrium help! For a reaction 2SO2(g) + O2(g) ↔ 2 SO3(g), 0.1mol of each SO2 and SO3 are mixed in a 2.0L flask at 27 degrees Celsius. After Equilibrium total pressure is 2.78atm. Calculate a) The mole fraction of O2 at equilibrium b) The value of Kp I don't know how to find out...
  9. D

    How Does Hydrogen Sulfide Affect pH and Precipitation in a Cu-Zn Solution?

    Homework Statement A sol'n contains Cu+2(aq) and Zn+2 ions each at a con'c of 0.1M. Hydrogen sulphide gas is bubbled up into sol'n and dissociates having an initial con'c of 0.1M. Whats the pH of the final solution? Will any precipate form? I don't know how to start the problem. Pls help me...
  10. C

    Chemical Equilibrium: Co(H2O)62+ + 4 Cl- ----> CoCl42- & 6 H2O

    I am totally confused with this question and have trying to figure it out for hours! Co(H2O)62+ (aq) + 4 Cl- (aq) ----> CoCl42- (aq) + 6 H2O (l) The equilibrium constant K = 4.82x 10-4 We begin by putting enough [Co(H2O)6]Cl2 (assume the salt dissociate completely into ions) into 100.0...
  11. M

    Solve 3 Chemical Equilibrium Questions & Calculate Kc

    Hi, I have 3 questions i can't seem to solve anyways thanks in advance. 1) If the equilbrium constant at a cetain temperature is 24 for the reaction, 2NO(g) <-> N2(g) + 02(g). Both of the systems listed below cannon be in equilbrium because at this temperature because there is only one value...
  12. C

    Chemical equilibrium: Enthelpies and equilibrium contsants

    Homework Statement For the system 2 CO2 = 2 CO + O2, ∆H= 510 kJ the percentage decomposition of CO2 changes w/ temperature as follows. Temp, K...% Decomposition 1500...0.048 2500...17.6 3000...54.8 Calculate the equilibrium constants, plot lnK vs. 1/T. In the graph, find the slope and...
  13. S

    Chemical Equilibrium Characteristics

    Consider the reaction: H2O(g) + CO(g) H2(g) + CO2(g) Which of the following statements are true and which are false. false Reactions with large equilibrium constants are always slow. false When Q > K the system will spontaneously shift to the right. false Amounts of all...
  14. H

    Solve Equilibrium for Chemical Reaction: 2A <-> B + C

    Homework Statement The following reaction initially contains [A]o = 0.2150 M and [B]o = [C]o = 0.4150 M. If the equilibrium constant for the reaction is Keq = 2.03, what are the concentrations of reactants and products when the reaction has achieved equilibrium? What is the value of deltaG for...
  15. M

    Are These Answers Correct for Chemical Equilibrium Questions?

    Can anyone please help me on these chem equilibrium questions. I just want to make sure if they are correct or not. 1. A chemical system in equilibrium will a. form more products if the the temperature is increased b. have a specific ratio of product to reactant concentrations c. not have...
  16. L

    How Do Different Stresses Affect a Chemical Equilibrium Reaction?

    1. Given the equilibrium reaction: N2(g) + O2(g) <---> 2NO(g) deltaH=180kJ mol-1 State the effect of each of the following potential stresses on the system: A) Temperature is decreased B) The pressure of the container is decreased, keeping volume constant C) A catalyst is added D) NO is...
  17. U

    Calculate K_C for N2, H2 System: 10.7M^2, 4.00M^2, 2.67M^2, 1.67M^2

    Homework Statement N_{2(g)}, 0.32M and H_{2(g)}, 0.66M are placed in a reaction vessel. The system reaches equilibrium when [H_{2(g)}] = 0.30M. Calculate K_C a) 10.7M^2 b) 4.00M^2 c) 2.67M^2 d) 1.67M^2 Homework Equations Equilibrium constant formulaThe Attempt at a Solution This is just...
  18. L

    Chemical equilibrium - Which side is the max entropy?

    Which side is the max entropy? P4(s) + 6H2(g) -> 4PH3(g) (delta H = +37 kJ)
  19. F

    Chemical Equilibrium Questions - Kc, Kp, Qp Calculations

    Hello, I have a few questions about my homework: (it is a rather long post, but I explained my work in detail, so everything is very clear -I hope-). 1) When we have a reaction such as: SO2 (g) + 1/2O2 (g) <=> SO3 (g) and then we have: 2SO2 (g) + O2 (g) <=> 2SO3 (g), we calculate Kc of...
  20. S

    Chemical Equilibrium (answer check)

    Consider the following reaction A(g) <---> 2B(g) + C(g) When 1.00 mol of A is placed in a 4.00L container at temperature t, the concentration of C at equilibrium is 0.050 mol/L. What is the equilibrium constant for the reaction at temperature t? Here is my answer: The balanced...
  21. R

    What is dynamic nature of chemical equilibrium?

    what is "dynamic nature" of chemical equilibrium? Explain what is meant by "dynamic nature" of chemical equilibrum?? thank you
  22. A

    Chemical Equilibrium: Opposite Answers Explained

    there are 2 Questions in which they seem like they should have the same answer, but apparently they dont, which is confusing. 1. 2NH3 <--> N2(g) + 3H2(g) initially, NH3 is added to empty flask. how do rates of forward and reverse reactions change as system proceeds towards eqm? answer...
  23. recon

    Chemical Equilibrium: K_c and Moles

    Chemistry is not one of my strong subjects, so please bear with me. Here's one of the questions we were given as homework, of which I'm having some trouble with. I'm sure it's pretty elementary, but the problem is that I'm unable to express the answer clearly enough. Question: The reaction...
  24. D

    Am I doing these Chemical Equilibrium Mass Action Expression problems correctly?

    I need help with the following questions. If you don't have time to solve both then please do the 2nd one. The answers I got are 1a .5 1b 1 1c not sure how to do it 2a 3.86 2b 2.42^13 Are they correct? 1) For the following reaction 2SO2 + O2 <_-_-_-_-_-> 2SO3 What...
  25. P

    Chemical Equilibrium, finding concentration

    H2(g) + I2(g) = 2HI(g) T = 731K K = 49.0 If at equilibrium 0.171 mol H2 and 1.571 mol I2 are present in a 1.04 L vessel, what is the concentration of HI in the gaseous mixture in moles/liter ? Ok I tried doing this question by setting up a mole ratio first...
  26. maverick280857

    Chemical Equilibrium Problem #2

    Hi again Here's another problem: When N_{2}O_{4} is allowed to dissociate to form NO_{2} at 15 degrees C at an equilibrium pressure of 1 atm, K_{p} = 0.41 for the reaction N_{2}O_{4}-->2NO_{2}. (a) If N_{2} is added to the system at constant volume will the equilbrium shift? (b) If the...
  27. maverick280857

    Calculating Equilibrium Amounts for Ammonium Hydrogen Sulfide Decomposition

    Hi everyone Here's the problem: The decomposition of ammonium hydrogen sulfide, NH_{4}HS(s) ----> NH_{3}(g) + H_{2}(g) (this rxn is reversible) is an endothermic process. A 6.1589 gm sample of solid is placed in an evacuated 4 litre vessel at exactly 24 degrees C. After equilibrium...
  28. himanshu121

    Is the Backward Reaction at Equilibrium Non-Spontaneous or Reversible?

    okay we say that reaction is spontaneous if \Delta G \le 0 consider a rxn at equilibrium A + B \rightleftharpoons C + D for forward rxn be spontaneous i.e \Delta G \le 0 then by rule backward rxn will be non spontaneous then WHY at equilibrium backward rxn taking place
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