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Chemical Equilibrium

Chemical Equilibrium. I. A State of Dynamic Balance. 1N 2 (g). +. 3H 2(g). 2NH 3(g). Δ G 0 = -33.1 kJ. The reaction is spontaneous under standard conditions. The concentrations of the reactants decrease at first…. But, then, before the reactants are used up, all concentrations

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Chemical Equilibrium

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  1. Chemical Equilibrium I. A State of Dynamic Balance 1N2 (g) + 3H2(g) 2NH3(g) ΔG0 = -33.1 kJ The reaction is spontaneous under standard conditions The concentrations of the reactants decrease at first… But, then, before the reactants are used up, all concentrations become constant …while the concentration of the product increases

  2. Chemical Equilibrium I. A State of Dynamic Balance -when a ________ results in the almost ________ conversion of ________ to ________, the ________ is said to go to __________, but _____ _________ ___ ____ go to __________, most _________ are __________ reaction complete reactants products 1N2 (g) + 3H2(g) 2NH3(g) reaction completion most reactions 1N2 (g) + 3H2(g) 2NH3(g) do not completion reactions reversible 1N2 (g) + 3H2(g) 2NH3(g) At first, only the reactants are present, so only the forward reaction can occur 1N2 (g) + 3H2(g) 2NH3(g)

  3. Chemical Equilibrium I. A State of Dynamic Balance -as soon as the ________ ________ begins, the ____________ of the _________ go _____, and the _________ _____ goes _____ as the number of __________ per unit ____ goes _____ forward reaction concentrations reactants down reaction rate down collisions time down As soon as the products begin forming, the forward reaction rate slows and the reverse reaction begins 1N2 (g) + 3H2(g) 2NH3(g)

  4. Chemical Equilibrium I. A State of Dynamic Balance -as the _________ proceeds, the ____ of the ________ _________ continues to ________ and the ____ of the ________ ________ continues to ________ until the two _____ are _____, and the system has reached a state of ________ __________ reaction rate forward reaction decrease rate reverse reaction increase rates equal chemical equilbrium 1N2 (g) + 3H2(g) 2NH3(g)

  5. Chemical Equilibrium I. A State of Dynamic Balance -at ___________, the ____________ of the ________ and ________ are not _____, but _______, because the ____ of _________ of the ________ is _____ to the ____ of _________ of the ________ equilibrium concentrations reactants products equal constant rate formation products equal rate formation reactants The Golden Gate Bridge connects San Francisco to Sausalito. If all other roads leading in and out of the two cities were closed… …and the number of vehicles crossing the bridge per hour in one direction equaled the number of vehicles crossing the bridge in the opposite direction… What is true of the number of vehicles in each city throughout the day? Are there the same number of vehicles in each city?

  6. Chemical Equilibrium II. Equilibrium Expressions and Constants -while _____ chemical systems have little tendency to _____, and _____ chemical systems _____ readily and ___ to __________, _____ chemical systems reach a _____ of __________, leaving varying amounts of ________ ____________ some react some react go completion most state equilibrium reactant unconsumed Waage -in 1864, Norwegian chemists ______ and _________ proposed the _______ ___________________, which states, at a given ___________, a chemical system may reach a _____ in which a particular _____ of _______ and _______ ____________ has a _______ value Guldberg Law of Chemical Equilibrium temperature state ratio reactant product concentrations constant Peter Waage 1833-1900 Cato Maximilian Guldberg 1836-1902

  7. Chemical Equilibrium II. Equilibrium Expressions and Constants -the _______ ________ for a _______ at __________ can be written ______________________________, where __ and __ are ________, __ and __ are ________, __, __, __, and __ are the ___________ in the ________ ________, and the __________ _______ __________ is general equation reaction equilibrium aA + bB cC + dD A B reactants C D products a b c d coefficients balanced equation equilibrium constant expression [C]c [D]d Keq = [A]a [B]b equilibrium mixtures Keq -___________ ________ with ___ values __ __ contain more ________ than ________ at ___________, while __________ ________ with ___ values __ __ contain more ________ than ________ at __________ > 1 products reactants equilibrium equilibrium mixtures Keq 1 < reactants products equilibrium

  8. Chemical Equilibrium II. Equilibrium Expressions and Constants Write the equilibrium constant expression for the homogeneous equilibrium for the synthesis of ammonia from nitrogen and hydrogen. 1N2 (g) + 3H2(g) 2NH3(g) The equilibrium is homogeneous because all the reactants and products are in the same physical state (gas) [C]c [D]d Keq = [A]a [B]b [C]c [NH3]c [NH3]2 Keq = = = [A]a [B]b [N2]a [H2]b [N2]1 [H2]3

  9. Chemical Equilibrium II. Equilibrium Expressions and Constants Write the equilibrium constant expression for the equilibrium for the synthesis of Hydrogen iodide from iodine and hydrogen. 1H2 (g) + 1I2(g) 2HI(g) The equilibrium is homogeneous because all the reactants and products are in the same physical state (gas) [C]c [D]d Keq = [A]a [B]b [C]c [HI]c [HI]2 Keq = = = [A]a [B]b [H2]a [I2]b [H2]1 [I2]1

  10. Chemical Equilibrium II. Equilibrium Expressions and Constants Write the equilibrium constant expression for the equilibrium for the decomposition of Dinitrogen tetroxide into Nitrogen dioxide. 1N2O4 (g) 2NO2(g) The equilibrium is homogeneous because all the reactants and products are in the same physical state (gas) [C]c [D]d Keq = [A]a [B]b [C]c [NO2]c [NO2]2 Keq = = = [N2O4]a [A]a [N2O4]1

  11. Chemical Equilibrium II. Equilibrium Expressions and Constants Write the equilibrium constant expression for the equilibrium for the reaction of Carbon monoxide and Hydrogen which produces methane (Tetrahydrogen monocarbide) and water. 1CO(g) + 3H2 (g) 1CH4(g) + 1H2O (g) [C]c [D]d Keq = [A]a [B]b [C]c [D]d [CH4]c [H2O]d [CH4]1 [H2O]1 Keq = = = [A]a [B]b [CO]a [H2]b [CO]1 [H2]3

  12. Chemical Equilibrium II. Equilibrium Expressions and Constants Write the equilibrium constant expression for the equilibrium for the decomposition of Dihydrogen monosulfide into diatomic hydrogen and diatomic sulfur. 2H2S (g) 2H2 (g) + 1S2 (g) [C]c [D]d Keq = [A]a [B]b [C]c [D]d [H2]c [S2]d [H2]2 [S2]1 Keq = = = [A]a [H2S]a [H2S]2

  13. Chemical Equilibrium II. Equilibrium Expressions and Constants -_________ in which all ________ and ________ are in the same ________ _____ are ____________, but ________ with _________ and ________ in _____ than ___ ________ _____ result in _____________ _________ equilibria reactants products physical state homogeneous reactions reactants products more one physical state heterogeneous gaseous ethanol equilibria 1C2H5OH (l) 1C2H5OH (g) [C]c [D]d Keq = [A]a [B]b [C2H5OH (g)]1 Keq = [C2H5OH (l)]1 Keq = [C2H5OH (g)]1 liquid ethanol

  14. Chemical Equilibrium II. Equilibrium Expressions and Constants -since ______ and _____ ________ and ________ don’t change ___________, (which is really their ______), if the ___________ remains ________, then in the ___________ _______ __________ for a ____________ ___________, the ___________ ________ only depends on the ______________ of the ________ and ________ in the _______ state of matter liquid solid reactants products concentration density temperature constant equilibrium constant expression heterogeneous equilibrium equilibrium constant concentrations reactants products gaseous

  15. Chemical Equilibrium II. Equilibrium Expressions and Constants Write the equilibrium constant expression for the heterogeneous equilibrium for the decomposition of Sodium Hydrogen carbonate into Sodium carbonate, Carbon dioxide, and water. 2NaHCO3 (s) 1Na2CO3 (s) + 1CO2 (g) + 1H2O (g) The equilibrium is heterogeneous because the reactants and products are in different physical states (gas and solid) [C]c [D]d [E]e Keq = [A]a Keq = [D]d [E]e = [CO2]d [H2O]e = [CO2]1 [H2O]1

  16. Chemical Equilibrium II. Equilibrium Expressions and Constants Write the equilibrium constant expression for the heterogeneous equilibrium for the decomposition of Calcium carbonate into Calcium oxide and Carbon dioxide. 1CaCO3 (s) 1CaO (s) + 1CO2 (g) The equilibrium is heterogeneous because the reactants and products are in different physical states (gas and solid) [C]c [D]d Keq = [A]a Keq = [D]d = [CO2]d = [CO2]1

  17. Chemical Equilibrium II. Equilibrium Expressions and Constants Write the complete, balanced thermochemical equation and equilibrium constant expression for the heterogeneous equilibrium for the reaction of monatomic Sulfur and fluorine gas, which produces Sulfur tetrafluoride gas and Sulfur hexafluoride gas. 2S (s) + 5F2 (g) 1SF4 (g) + 1SF6 (g) [SF4]1 [SF6]1 Keq = [F2]5

  18. Chemical Equilibrium II. Equilibrium Expressions and Constants Write the complete, balanced thermochemical equation and equilibrium constant expression for the homogeneous equilibrium for the reaction of hydrazine (Tetrahydrogen dinitride) and Nitrogen dioxide, which produces nitrogen and water. 2N2H4 (g) + 2NO2 (g) 3N2 (g) + 4H2O (g) [N2]3 [H2O]4 Keq = [N2H4]2 [NO2]2

  19. Chemical Equilibrium II. Equilibrium Expressions and Constants Write the complete, balanced thermochemical equation and equilibrium constant expression for the homogeneous equilibrium for the reaction of Sulfur trioxide and Carbon dioxide, which produces Carbon disulfide and oxygen. 2SO3 (g) + 1CO2 (g) 1CS2 (g) + 4O2 (g) [CS2]1 [O2]4 Keq = [SO3]2 [CO2]1

  20. Chemical Equilibrium II. Equilibrium Expressions and Constants Write the complete, balanced thermochemical equation and equilibrium constant expression for the heterogeneous equilibrium for the reaction of monatomic Sulfur and fluorine gas, which produces Sulfur tetrafluoride gas and Sulfur hexafluoride gas. 2S (s) + 5F2 (g) 1SF4 (g) + 1SF6 (g) [SF4]1 [SF6]1 Keq = [F2]5

  21. Chemical Equilibrium II. Equilibrium Expressions and Constants Write the complete, balanced thermochemical equation and equilibrium constant expression for the heterogeneous equilibrium for the reaction of magnatite (Fe3O4) and hydrogen gas, which produces iron and water vapor. 1Fe3O4 (s) + 4H2 (g) 3Fe (s) + 4H2O (g) [H2O]4 Keq = [H2]4

  22. Chemical Equilibrium II. Equilibrium Expressions and Constants Write the equilibrium constant expression for the homogeneous equilibrium for the synthesis of ammonia and calculate the value of Keq when [NH3] = 0.933 M, [N2] = 0.533 M, and [H2] = 1.600 M. 1N2 (g) + 3H2(g) 2NH3(g) [NH3]2 Keq = [N2]1 [H2]3 [0.933]2 Keq = [0.533]1 [1.600]3 Keq = 0.399

  23. Chemical Equilibrium II. Equilibrium Expressions and Constants Write the equilibrium constant expression for the homogeneous equilibrium for the decomposition of Sulfur trioxide into Sulfur dioxide and oxygen gas, and calculate the value of Keq when [SO3] = 0.0160 M, [SO2] = 0.00560 M, and [O2] = 0.00210 M. 2SO3 (g) 2SO2 (g) + 1O2 (g) [SO2]2 [O2]1 Keq = [SO3]2 [0.00560]2 [0.00210]1 Keq = [0.0160]2 Keq = 2.58 x 10-4

  24. Chemical Equilibrium III. Le Châtelier’s Principle 1. Hypothesis: What is the effect of temperature on equilibrium? 2. Prediction: 3. Gather Data: A. Safety: The surfaces of the hot plates and the water will be hot enough to cause burns. Use caution. Cobalt(II) chloride hexahydrate is toxic, with an LD50 = 80mg/kg Avoid ingestion (don’t eat or drink it). Wash hands thoroughly with soap and water before leaving lab. Ethanol is extremely flammable. No open flame. B. Procedure: 1. Pick up a sheet of white construction paper and an artist’s paintbrush.

  25. Chemical Equilibrium III. Le Châtelier’s Principle 3. Gather Data: B. Procedure: 2. With a partner, using a top-loading electronic balance, mass 0.3 grams of CoCl2·6H2O, crush it into a fine powder using a mortar and pestle, and place it in a test tube. 3. Add 10 mL of ethanol to the test tube, cap, and shake vigorously until CoCl2·6H2O dissolves. If the solution is not light pink, add water dropwise until it turns light pink. 4. Use the solution to paint a winter scene on your white construction paper, including a pink-colored field of snow. 5. To simulate the coming of spring, warm your painting over the hotplate in the fume hood. Record your observations.

  26. Chemical Equilibrium III. Le Châtelier’s Principle 4. Analyze Data: 1Co(H2O)62+ (aq) + 4Cl- (aq) 1CoCl42-(aq) + 6H2O (l) + heat Hexahydrate Co2+ ion (pink) chloride ion Tetrachlorocobaltate ion (blue) 1Co(H2O)62+ (aq) + 4Cl- (aq) 1CoCl42-(aq) + 6H2O (l) Hexahydrate Co2+ ion (pink) chloride ion Tetrachlorocobaltate ion (blue) 5. Draw Conclusions:

  27. Chemical Equilibrium III. Le Châtelier’s Principle -________ that reach __________ instead of going to __________ do not ________ as much reactions equilibrium completion produce -in 1888, ________________________ discovered that there are ways to _______ _________ in order to make _________ more __________ Henry-Louis Le Châtelier control equilibria reactions productive -____________________ states that if a ______ (like a ______ in __________) is applied to a system at __________, the system _____ in the ________ that _______ the _____ Le Châtelier’s Principle stress change temperature equilibrium shifts direction relieves stress Henry-Louis Le Châtelier 1850-1936

  28. Chemical Equilibrium III. Le Châtelier’s Principle -stressors that cause a shift in equilibrium A. Changes in Concentration Write the equilibrium constant expression for the equilibrium for the reaction of Carbon monoxide and Hydrogen to produce methane and water. Then, calculate the Keq value when [CO] = 0.30000 M, [H2] = 0.10000 M, and [CH4] = 0.05900 M, and [H2O] = 0.02000 M. 1CO(g) + 3H2 (g) 1CH4(g) + 1H2O (g) [CH4]1 [H2O]1 Keq = [CO]1 [H2]3 [0.05900]1 [0.02000]1 Keq = = 3.933 = first equilibrium position [0.30000]1 [0.10000]3

  29. Chemical Equilibrium III. Le Châtelier’s Principle A. Changes in Concentration increasing concentration -_________ the ____________ of ___ _________ the _______ of _________ between ___ and ___, _________ the _____ of the _______ _______ CO increases number collisions CO H2 increasing rate forward reaction 1CO(g) + 3H2 (g) 1CH4(g) + 1H2O (g) -the system responds to the ______ of the addition of _______ by forming more _______ to bring the system back into equilbrium stress reactant product

  30. Chemical Equilibrium III. Le Châtelier’s Principle A. Changes in Concentration 1CO(g) + 3H2 (g) 1CH4(g) + 1H2O (g) 0.99254 M 0.07762 M 0.06648 M 0.02746 M [CH4]1 [H2O]1 Keq = [CO]1 [H2]3 [0.06648]1 [0.02746]1 Keq = = 3.933 = second equilibrium position [0.99254]1 [0.07762]3

  31. Chemical Equilibrium III. Le Châtelier’s Principle A. Changes in Concentration increasing concentration -_________ the ____________ of a ________ causes __________ to _____ to the ____ to _______ the ____ of formation of ______ reactant equilbrium shift right increase rate product 1CO(g) + 3H2 (g) 1CH4(g) + 1H2O (g) 1CO(g) + 3H2 (g) 1CH4(g) + 1H2O (g) decreasing concentration -_________ the ____________ of a ________ causes __________ to _____ to the ____ to _______ the ____ of formation of ______ product equilbrium shift right increase rate product

  32. Chemical Equilibrium III. Le Châtelier’s Principle A. Changes in Concentration Predict what should happen to the following equilibrium if hydrogen bonding due to the addition of acetone binds water and effectively removes it from the products. 1Co(H2O)62+ (aq) + 4Cl- (aq) 1CoCl42-(aq) + 6H2O (l) Hexahydrate Co2+ ion (pink) chloride ion Tetrachlorocobaltate ion (blue)

  33. Chemical Equilibrium III. Le Châtelier’s Principle -stressors that cause a shift in equilibrium A. Changes in Volume -_________ the ______ of the _______ container, according to ______, ________ the ________, which in turn ________ the _____ of _________ between the ________ of the ________, _________ the _____ of the ________ _______ decreasing volume reaction Boyle increases pressure 1CO(g) + 3H2 (g) increases rate collision particles reactants increasing rate forward reaction 1CH4(g) + 1H2O (g) shift equilibrium -the _____ in the _________ causes the _____ on the system to be _______ as for every __ _____ of _______ _______ _________, only __ _____ of _______ _______ are _________, which, according to ________, occupies __ the ______, which _________ the ________ stress relieved 4 moles gaseous reactant consumed 2 moles gaseous product produced Avogadro ½ volume decreases pressure

  34. Chemical Equilibrium III. Le Châtelier’s Principle -stressors that cause a shift in equilibrium Use Le Châtelier’s Principle to predict how each of these changes would affect the ammonia equilibrium system. 1N2 (g) + 3H2(g) 2NH3(g) a. removing hydrogen from the system __________________________ equilibrium shifts to the left 1N2 (g) + 3H2(g) 2NH3(g) b. adding ammonia to the system _______________________________ equilibrium shifts to the left 1N2 (g) + 3H2(g) 2NH3(g)

  35. Chemical Equilibrium III. Le Châtelier’s Principle -stressors that cause a shift in equilibrium Use Le Châtelier’s Principle to predict how each of these changes would affect the ammonia equilibrium system. 1N2 (g) + 3H2(g) 2NH3(g) c. adding hydrogen to the system _______________________________ equilibrium shifts to the right 1N2 (g) + 3H2(g) 2NH3(g)

  36. Chemical Equilibrium 2SO2 (g) + 1O2(g) 2SO3(g) III. Le Châtelier’s Principle -stressors that cause a shift in equilibrium How would decreasing the volume of the reaction container affect each of these equilibria? a. _________________________ equilibrium shifts to the right b. _____________________________ 1H2 (g) + 1Cl2(g) 2HCl(g) stress has no effect on equilibrium c. _________________________ 2NOBr(g) 2NO(g) + 1Br2(g) equilibrium shifts to the left

  37. Chemical Equilibrium III. Le Châtelier’s Principle -stressors that cause a shift in equilibrium A. Changes in Temperature -while _______ in _____________ and ________ in _______ cause ______ in _________, they ___ ___ _______ the __________ _______, but a ______ in ___________ causes ______ in both the __________ ________ and the __________ _______ changes concentration changes volume shifts equilibria do not change equilibrium constant change temperature change equilibrium position equilibrium constant

  38. Chemical Equilibrium III. Le Châtelier’s Principle -stressors that cause a shift in equilibrium A. Changes in Temperature -since the _______ for making _______ has a _______ ____, the ________ _______ is _________, and the _______ _______ is __________, so ____ can be thought of as a _______ in the ________ _______ and a _______ in the _______ _______ reaction methane negative ΔH0 forward reaction exothermic 1CO(g) + 3H2 (g) reverse reaction endothermic heat product forward reaction reactant reverse reaction 1CH4(g) + 1H2O (g) + heat ΔH0 = -206.5 kJ

  39. Chemical Equilibrium III. Le Châtelier’s Principle -stressors that cause a shift in equilibrium A. Changes in Temperature -_________ the __________ is like _______ more _______ to the _______ in which _____ acts as a _______ and is _____ ___, in this case, the __________ _______ _______ increasing temperature adding reactant reaction heat reactant used up endothermic reverse reaction 1CO(g) + 3H2 (g) 1CH4(g) + 1H2O (g) + heat equilibrium left -__________ shifts to the _____, _________ the ___________ of _______ because _______ is a _______ in the _______ _______ decreasing concentration methane methane reactant reverse reaction

  40. Chemical Equilibrium III. Le Châtelier’s Principle -stressors that cause a shift in equilibrium In the following equilibrium, would you raise or lower the temperature to get the following results? 1C2H2 (g) + 1H2O(g) 1CH3CHO(g) ΔH0 = -151 kJ a. increase the amount of CH3CHO______________________________ lower the temperature 1C2H2 (g) + 1H2O(g) 1CH3CHO(g) + heat b. decrease the amount of C2H2 ________________________________ lower the temperature 1C2H2 (g) + 1H2O(g) 1CH3CHO(g) + heat

  41. Chemical Equilibrium III. Le Châtelier’s Principle -stressors that cause a shift in equilibrium In the following equilibrium, would you raise or lower the temperature to get the following results? 1C2H2 (g) + 1H2O(g) 1CH3CHO(g) ΔH0 = -151 kJ c. increase the amount of H2O _________________________________ raise the temperature 1C2H2 (g) + 1H2O(g) 1CH3CHO(g) + heat

  42. Chemical Equilibrium III. Le Châtelier’s Principle -stressors that cause a shift in equilibrium In the following equilibrium, what effect does decreasing the volume of the reaction vessel have? 1CO(g) + 1Fe3O4(s) 1CO2 (g) + 3FeO(s) ______________________________________________________________________________________________________________________________________________________________________________ None. The solids do not change their concentrations, and the number of moles of gaseous reactant equals the number of moles of gaseous product In the following equilibrium, what effect does simultaneously increasing the temperature and the pressure have? 1CO (g) + 1Cl2(g) 1COCl2(g) + heat ΔH0 = -151 kJ ______________________________________________________________________________________________________________________________________________________________________________ Cannot predict. An increase in temperature causes a shift in the equilibrium to the left, while an increase in pressure causes a shift in equilibrium to the right.

  43. Chemical Equilibrium III. Le Châtelier’s Principle 1. Hypothesis: What is the effect of a change in concentration of reactants and a change in temperature on equilibrium? 2. Prediction: 3. Gather Data: A. Safety: The surfaces of the hot plate will be hot enough to cause burns. Use caution. Cobalt(II) chloride hexahydrate is toxic, with an LD50 = 80mg/kg Avoid ingestion (don’t eat or drink it). Wash hands thoroughly with soap and water before leaving lab. Concentrated Hydrochloric acid is extremely corrosive. Avoid contact with eyes, skin, and clothing. Goggles, aprons, and gloves mandatory.

  44. Chemical Equilibrium III. Le Châtelier’s Principle 3. Gather Data: B. Procedure: 1. With a partner, measure out 2 mL of 0.1 M CoCl2 solution into a test tube. Record initial color. __________ 2. Add 3 mL (60 drops) of concentrated HCl to the test tube. Record color. _____________ 3. Add water dropwise to the test tube until a color change occurs. Record color. ______________ 4. Add 2 mL of 0.1 M CoCl2 solution to another test tube. Add concentrated HCl dropwise until the solution turns purple. If the solution turns blue, add water until it turns purple.

  45. Chemical Equilibrium 1Co(H2O)62+ (aq) + 4Cl- (aq) 1CoCl42-(aq) + 6H2O (l) Hexahydrate Co2+ ion (pink) chloride ion Tetrachlorocobaltate ion (blue) III. Le Châtelier’s Principle 3. Gather Data: B. Procedure: 5. Place the test tube in an ice bath. Record color. ________ 6. Place the test tube in a hot water bath. Record color. ___________ 4. Analyze Data: A. The equation for the reversible reaction in this experiment is: + heat

  46. Chemical Equilibrium III. Le Châtelier’s Principle 4. Analyze Data: A. Use the equation to explain the colors of the solution in steps 1, 2, and 3 In Step 1, the solution is initially a pink color, because the reaction arrives at an equilibrium in which the concentration of the pink-colored 1Co(H2O)62+(aq) is at a higher concentration than the blue-colored 1CoCl42-(aq). In Step 2, the addition of HCl increases the concentration of Cl-, shifting the equilibrium to the right to favor the formation of the blue 1CoCl42-(aq), so the solution turns blue. In Step 3, the increase in concentration of water shifts the equilibrium left, re-establishing a new equilbrium where the concentration of 1CoCl42-(aq) is higher than it was orginally, so the purple color shows more of a balance of pink and blue.

  47. Chemical Equilibrium III. Le Châtelier’s Principle 4. Analyze Data: B. Explain how the equilibrium shifts when heat energy is added or removed. In Step 5, since heat acts like a product in the exothermic reverse reaction, removing heat by lowering the temperature causes the equilibrium to shift to the left, increasing the rate of the reverse reaction and causing the solution to turn pink. In Step 6, since heat acts like a reactant in the endothermic forward reaction, adding heat by increasing the temperature causes the equilibrium to shift to the right, increasing the rate of the forward reaction and causing the solution to turn blue. 5. Draw Conclusions:

  48. Chemical Equilibrium IV. Using Equilibrium Constants -when a ________ has a _____ ___, the __________ _______ contains _____ ________ than ________ at __________ reaction large Keq equilibrium mixture more products reactants equilibrium -when a ________ has a _____ ___, the __________ _______ contains _____ ________ than ________ at __________ reaction small Keq equilibrium mixture more reactants products equilibrium A. Calculating Equilibrium Concentrations -__________ ________ can also be used to ________ the __________ ____________ of any ________ in the _______ equilibrium constants calculate equilibrium concentration substance reaction

  49. Chemical Equilibrium IV. Using Equilibrium Constants A. Calculating Equilibrium Concentrations At 1200 K, the Keq for the following reaction equals 3.933. What is the concentration of the methane produced, if [CO] = 0.850 M, [H2] = 1.333 M, and [H2O] = 0.286 M? 1CO(g) + 3H2 (g) 1CH4(g) + 1H2O (g) 1.333 M 0.850 M ? M 0.286 M [CH4]1 [H2O]1 Keq = [CO]1 [H2]3 [CH4]1 [0.286]1 3.933 = [0.850]1 [1.333]3 [CH4] = 27.7 M

  50. Chemical Equilibrium IV. Using Equilibrium Constants A. Calculating Equilibrium Concentrations At 1405 K, the Keq for the following reaction equals 2.27 x 10-3. What is the concentration of the Hydrogen gas produced, if [S2] = 0.0540 M, and [H2S] = 0.184 M? 2H2S (g) 2H2(g) + 1S2 (g) 0.184 M ? M 0.0540 M [H2]2 [S2]1 Keq = [H2S]2 [H2]2 [0.0540]1 2.27 x 10-3 = [0.184]2 [H2] = 0.0377 M

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