Which of the following factors will not alter the position of equilibrium?

Transcription

1 86 N( g) + 3H $ ( g) NH3 ( g) Which of the following factors will not alter the position of uilibrium? A a pressure decrease B a temperature increase C the presence of a catalyst D the addition of more N ( g) 87 NO 4( g) + energy $ NO( g) Which of the following graphs shows the result of increasing the temperature at time? (1 mark) A B Concentration NO N O 4 Concentration NO N O 4 C D Concentration NO N O 4 t1 Concentration NO N O 4 88 N O $ ( g) NO ( g) 4 Initial Equilibrium [ NO 4 ] [ NO ] [ NO 4 ] [ NO ] Trial Trial Which of the following represents the value? A B C D 16 1

2 89 Which of the following is least likely to favour the formation of products? A HO ( g) H( g) O( g) = B NO( g) NO( g) 3NO( g) = C NO4( g) NO( g) = 45 D SO( g) NO( g) NO( g) SO3 ( g) = 85 9 Consider the following uilibrium: N( g) + 3H # ( g) NH3 ( g) What is the final result of adding some NH 3 gas to the system at constant volume? A increases B H [ ] decreases [ ] decreases C NH 3 D remains unchanged 91 CO( g) + O # ( g) CO( g) A container is initially filled with CO and O How will the CO change as the system reaches uilibrium? [ CO] [ CO ] A increase decrease B increase increase C decrease decrease D decrease increase [ ] [ ] and CO

3 9 Two experiments were performed involving the following uilibrium The temperature was the same in both experiments H( g) + I( g) Æ HI( g) In experiment A, 1 M H and 1 M I were initially added to a flask and uilibrium was established In experiment B, M HI was initially added to a second flask and uilibrium was established Which of the following statements is always true about the uilibrium concentrations? A [ H ] uals [ HI] in experiment A B HI [ ] uals [ H] in experiment A C [ HI] in experiment A uals [ HI] in experiment B 93 D HI [ ] in experiment A uals 1 I [ ] in experiment B Which of the following reactions is accompanied by an increase in enthalpy? A NO( g) + O( g) Æ NO( g) + 113kJ B H( g) + O( g) 484 kj Æ HO( g) C SO3( g) Æ SO( g) + O( g) DH = kj D 4HCl( g) + O( g) Æ HO( g) + Cl( g) D H = 111 4kJ 94 Two substances are mixed and no reaction occurs With respect to enthalpy and entropy, which of the following could explain why no reaction occurs? Enthalpy Entropy A increases increases B increases decreases C decreases increases D decreases decreases

4 95 N( g) + 3H( g) Æ NH3( g) Which of the following diagrams represents what happens to the forward and reverse reaction rates when the catalyst Fe O 3 4 is added? A B forward rate forward rate reverse rate reverse rate C D forward rate forward rate reverse rate reverse rate 96 Temperature is gradually decreased then held constant in an exothermic uilibrium Which of the following represents the change in the reverse reaction rate? A B reverse reaction rate reverse reaction rate time time C D reverse reaction rate reverse reaction rate time time

5 97 CaCO3( s) + HF( g) Æ CaF( s) + HO( g) + CO( g) [ ] [ ] HF B [ HO ]= CO [ ] [ ]? Which of the following represents the uilibrium HO [ HF] HF CaCO3 A [ HO ]= C [ [ ] [ ] HO ]= CO CO CaF [ ][ ] [ ] [ 3] [ ][ ] HF CaCO D [ HO ]= CO CaF Which of the following reactions will proceed furthest toward completion? A Si( s) + O( g) Æ SiO( s) = 1 B HBr( g) Æ H( g) + Br( g) = 7 1 C HO ( g) Æ H( g) + O( g) = D CH 4( g) + H( g) Æ CH 6( g) = CH4( g) + HO( g) Æ CO( g) + 3H( g) = An uilibrium mixture of this system was found to contain the following concentrations: [ CH4]= 59 M, [ HO ]= 63M, [ CO]= 5 M What was the uilibrium H A 6 M B 64 M C M D 84 M [ ]? 1 H( g) + I( g) Æ HI( g) = 49 5 at 44 C If 5 M HI is initially placed into a container, what will be the uilibrium HI [ ]? A 33 M B 39 M C 44 M D 48 M 11 H( g) + I( g) Æ HI( g) = 49 5 at 44 C If 1 M H, 1M I and 844M HI are placed into a container at 44 C, which of the following is true as uilibrium is approached? [ ] decreases significantly [ ] decreases significantly [ ] decreases significantly [ ] remains the same A I B HI C H D H

6 1 A small amount of HCl is added to the following uilibrium system: + CrO4 ( aq) + H ( aq) Æ CrO 7 ( aq) + HO l How do the [ CrO 4 ] and the reverse reaction rate change as uilibrium is reestablished? [ CrO 4 ] Reverse Rate A increases increases B increases decreases C decreases decreases D decreases increases ( ) N O colourless Æ ( g) NO ( g) 4 brown If NO 4 is placed in a flask at a constant temperature, which of the following is true as the system approaches uilibrium? A The colour gets darker as NO B The colour gets lighter as NO C The colour gets darker as NO 4 D The colour gets lighter as NO 4 NO Æ 4( g) NO( g) colourless brown [ ] increases [ ] decreases [ ] increases [ ] decreases The system above reaches uilibrium Considering enthalpy and entropy factors, which of the following is true with respect to the forward reaction? A The entropy is increasing and the reaction is exothermic B The entropy is decreasing and the reaction is exothermic C The entropy is increasing and the reaction is endothermic D The entropy is decreasing and the reaction is endothermic 15 In which of the following reactions do the tendencies for minimum enthalpy and maximum entropy both favour reactants? A? 3O( g) Æ O3( g) DH =+ 85 kj B? N( g) + 3H( g) Æ NH3( g) DH =9 kj C? BrCl( g) Æ Br( g) + Cl( g) DH = 9 3 kj D? CaCO3( s) Æ CaO( s) + CO( g) DH = kj

7 16 CaCO3( s) Æ CaO( s) + CO( g) DH = kj Which of the following diagrams best represents the change in the concentration of CO as temperature is decreased at time? A B [ CO ] [ CO ] C D [ CO ] [ CO ] 17 The Haber Process is used to produce ammonia commercially according to the following uilibrium: N( g) + 3H( g) Æ NH3( g) + energy Which of the following conditions will produce the highest yield of ammonia? A increase temperature and increase pressure B increase temperature and decrease pressure C decrease temperature and increase pressure D decrease temperature and decrease pressure 18 CrO 7 ( aq) + OH ( aq) Æ CrO4 ( aq) + HO( l ) = 4 14 The concentration of ions at uilibrium was measured at a specific temperature and found to be [ CrO 7 ]= 1 M and [ OH ]= M What is the uilibrium CrO 4 M A B C D 1 1 M M M [ ]?

8 19 In which of the following uilibria does the concentration of reactants ual the concentration of products? A NO4( g) Æ NO( g) = 71 + B H ( aq) + OH ( aq) Æ HO( l ) = 1 1 C CO( g) + H( g) Æ CO( g) + HO( g) = 79 D SnO( s) + H( g) Æ Sn( s) + HO( g) = C( s) + HO( g) Æ CO( g) + H( g) At uilibrium, 4 1 mol H, 4 1 mol CO, 1 1 mol HO and 1 1 mol C were present in a 1 L container What is the value of? A 63 B 16 C 63 D ( ) Æ ( ) + ( ) COF g CO g CF4 g Initially, 1 M CO and M CF 4 are placed in a container At uilibrium, it is found that the COF M What is the value of? A 89 B 45 C 8 D 11 [ ] is 4 11 Reacting systems tend toward which of the following? Entropy Enthalpy A minimum maximum B minimum minimum C maximum minimum D maximum maximum

9 113? NH NO Æ 4 3( s) NO( g) + HO( g) DH = 37 kj Which of the following is true? Enthalpy Entropy Outcome A favours reactants favours reactants reaction does not occur B favours products favours products reaction goes to completion C favours reactants favours products reaction reaches uilibrium D favours products favours reactants reaction reaches uilibrium 114 energy + ClO3( s) Æ Cl( s) + 3O( g) Which of the following will cause a shift to the left? A adding more O B adding more Cl C removing some ClO 3 D increasing the temperature 115 N( g) + 3H( g) Æ NH3( g) + energy The following diagram represents the rate of the reverse reaction Rate of Reverse Reaction Which of the following stresses explains what happened at? [ ] increased [ ] decreased [ ] increased [ ] decreased A H B N C NH 3 D NH 3

10 116 Limestone is decomposed to make quicklime ( CaO) according to the following uilibrium: CaCO3( s) + 175kJ Æ CaO( s) + CO( g) Which of the following conditions would produce the greatest yield of CaO( s )? Temperature Pressure A low low B low high C high low D high high H( g) + O H O ( g) Æ ( l ) Which of the following represents the concentration of O at uilibrium? Ê A [ O]= Á Ë 1 H [ ] ˆ [ ] [ ] Ê HO C [ O]= Á Ë H ˆ [ ]= [ ] B O H D [ O ]= 1 H [ ] CrO 4 ( H CrO H 7 O aq) + ( aq) Æ ( aq) + ( l) A solution of Ba( NO 3 ) is added, and a precipitate of BaCrO 4 forms In which direction will the uilibrium shift, and what will happen to the value of? A Equilibrium shifts left, and decreases B Equilibrium shifts right, and increases C Equilibrium shifts left, and remains constant D Equilibrium does not shift, and remains constant

11 119 CH4( g) + HO( l) Æ CO( g) + 3H( g) At uilibrium, 1 mol CH 4, 1 mol HO, 8 mol CO and 4 mol H are present in a 1 L container What is the value of? A B C D NO( g) + H( g) Æ N( g) + HO( g) Initially, 1 mol NO, 5 mol H and 1 mol HO are placed in a 1 L container At uilibrium, the [ HO ]= 138 M What is the value of? A 35 B C D WrittenSolution Questions: 11 COF( g) CO( g) + CF4( g) = A L container is filled with 5 mol of COF Calculate the [ COF ] at uilibrium 1 + aq aq 4 aq Cu ( ) + 4Br ( ) CuBr blue colourless green ( ) Cooling the uilibrium changes the colour from green to blue What effect will the decrease in temperature have on? Explain, using Le Chatelier s Principle 13 A flask is initially filled with some HI At uilibrium, the [ HI]= 8 mol L What is the H [ ] at uilibrium? HI( g) H( g) + I( g) = 5

12 14 NOCl ( g) NO( g) + Cl( g) = A 1 L flask is filled with mol NOCl, 1 mol NO and 1 mol Cl State and show by calculation the direction in which the reaction proceeds to reach uilibrium H( g) + Br ( g) HBr( g) = 14 8 A closed container was initially filled with ual moles of H and Br When uilibrium is reached, the [ HBr] is 39 mol L What was the initial H Write four statements that apply to all chemical uilibrium systems [ ]? ( 17 i) H( g) + I ( g) HI( g) Concentration (mol L) HI H I t t 3 The temperature is increased at and uilibrium is reestablished at t a) On the above graph, sketch the line representing the [ HI] between time and t 3 b) Calculate the value of after t 18 SO( g) + O ( g) SO3 ( g) A 1 L container is initially filled with 1 mol SO and 1 mol O At uilibrium the O concentration is 6 mol L Calculate the value of

13 19 ( ) ( ) NF g NF4 g Equilibrium shifts to the right when volume is decreased Describe the changes in reaction rates that cause this shift to the right 13 H( g) + I ( g) HI( g) Initially, mol H and mol I are added to an empty L container At uilibrium, the [ I]= mol L What is the value of? State Le Chatelier s Principle CH4( g) + HO ( g) CO( g) + 3H( g) 5 Consider the following uilibrium and accompanying graph: Initially, 6 mol CH 4, 8 mol HO, 8 mol CO and 74 mol H are placed into a 4 L container At uilibrium, the [ H]= Zn mol ( IOL 3) What + ( s) is Zn ( aq) + IO3 ( aq) the value of? Chemical reactions tend toward a position of minimum enthalpy and maximum entropy a) What is meant by the term enthalpy? b) What is meant by the term entropy? [ Ions] [ IO 3 ] [ Zn + ] H( g) + Br ( g) HBr( g) = t t 3 Initially, 8 mol H and 8 mol Br are placed into a 4 L container What is the [ HBr] at uilibrium? a) Identify the stress applied at ( ) + s aq + 3 aq Zn IO3 ( ) Zn ( ) IO [ IO 3 ] ( ) a) Identify the stress applied at b) Complete the above graph from to t 3 for the [ IO 3 ] [ Ions] [ Zn + ] 6 Calculate the solubility of SrSO 4 in grams per litre t t 3

14 Describe the nature of dynamic uilibrium N O 4( g) NO( g) = Initially, 6 mol NO 4 and mol NO are placed into a L container Use calculations to determine the direction in which the reaction proceeds in order to reach uilibrium 138 CH4( g) + HO $ ( g) CO( g) + 3H( g) Temperature C C Is the forward reaction in this uilibrium exothermic or endothermic? Explain your answer 139 CO( g) + Cl $ ( g) COCl( g) At uilibrium, the system contains mol CO, 1 mol Cl and mol COCl in a L container Calculate the value of 14 N( g) + 3H $ ( g) NH3 ( g) DH =9 kj The system is normally maintained at a temperature of approximately 5 C a) Explain why 1 C is not used b) Explain why 1 C is not used 141 SO3 ( g) + NO( g) $ NO( g) + SO( g) In an experiment, 1 moles of SO 3 and 1 moles of NO are placed in a 1 L container When uilibrium is achieved, [ NO]= 414 mol L Calculate the value 14 C3H8 ( g) + 5O? ( g) 3CO( g) + 4HO! ( g) Explain, in terms of increasing or decreasing entropy and enthalpy, whether or not the reaction will reach uilibrium

15 143 H( g) + I $ ( g) HI ( g) = 64 Equal moles of H, I and HI are placed in a 1 L container Use calculations to determine the direction the reaction will proceed in order to reach uilibrium 144 H( g) + I $ ( g) HI( g) The system is said to shift right as the result of the addition of extra H ( g) Describe the suence of changes in both forward and reverse reaction rates as the system goes from the original uilibrium to the new uilibrium 145 NO( g) + Cl( g) $ NOCl( g) = 85 A closed flask is found to contain 4 M NO ( g), 3 M Cl( g) and 56 M NOCl ( g) Use appropriate calculations to determine the direction the reaction proceeds to reach uilibrium ( ) ( ) Æ ( ) ( ) + Al HO 4 OH Al HO OH H ( aq) 3 3( s) ( aq) + a) Some HCl( aq ) is added to the uilibrium What happens to the amount of solid Al H O OH ( ) ( )? Explain 3 3 b) The HCl is added at time and uilibrium is reestablished at time t On the axis below, sketch what happens to the reverse reaction rate Reverse Reaction Rate t

16 a) Calculate the value of at 147 NO4( g) Æ NO( g) b) DCalculate H =+ 59 kj the value of at t NO a) Calculate the value of at b) Calculate the value of at t 3 c) What stress was applied at time t? Explain Concentration (M) 6 6 N O 4 Stress: Explanation: c) What stress was applied at time t? Expla Stress: 148 Consider the following uilibrium: t N( g) + O( g) Æ NO( g) = 95 t 3 Explanation: Initially, 15 mol N and 15 mol O were placed in a 1 L container Consider Calculate the the following concentration uilibrium: of all species at uilibrium (4 marks) 149 N( g) + O( g) Æ NO( g) = A L container is filled with 15 mol N, 15 mol O and 5 mol NO Does the NO answer with appropriate calculations [ ] increase or decrease as uilibrium is established? Support your 1 (4 marks) 3 Calculate the iodate ion concentration in a saturated copper (II) iodate solution at 5 C (3 marks)

17 MultipleChoice Answers 1 A 6 C 11 D 16 A 1 C 6 B 31 B 36 C 41 A 46 D D 7 A 1 B 17 A C 7 B 3 C 37 B 4 B 47 B 3 C 8 C 13 A 18 D 3 C 8 A 33 D 38 C 43 D 48 D 4 C 9 A 14 D 19 C 4 B 9 D 34 A 39 D 44 A 49 D 5 D 1 B 15 A A 5 A 3 D 35 C 4 B 45 A 5 B 51 C 56 C 61 D 66 C 71 D 76 D 81 A 86 C 91 D 96 B 5 A 57 A 6 B 67 A 7 C 77 A 8 D 87 A 9 C 97 B 53 C 58 A 63 C 68 C 73 B 78 A 83 B 88 A 93 C 98 A 54 A 59 B 64 A 69 C 74 A 79 A 84 A 89 A 94 B 99 C 55 C 6 B 65 A 7 B 75 D 8 C 85 C 9 D 95 A 1 B 11 D 16 A 111 D 116 C 1 D 17 C 11 C 117 A 13 A 18 C 113 B 118 C 14 C 19 D 114 A 119 A 15 A 11 B 115 C 1 B

18 WrittenSolution Answers: 11 COF( g) CO( g) CF4( g) [] I 5 mol = 5 mol L L [ C] x + x + x [ E] 5 x x x [ CO ][ CF ] 4 = COF [ ] = ( )( ) ( ) x x 5 x x = 93 mol L [ COF ]= 5 x = 5 ( 93) = 65 mol L 1 13 The value of decreased When the temperature stress is applied to the uilibrium system, the system shifts to the left to offset the stress and in the new uilibrium, the products [ ] has decreased = 5 [ H][ I] HI [ ] x x = ( )( ) ( 8) x = 4 [ H]= 4 M

19 14 Direction: Reaction proceeds to the left Calculations: NOCl( g) NO( g) + Cl( g) Trial Trial NO Cl = [ ] [ ] NOCl > [ ] = ( ) 1 ( 1 ) ( ) = 5 15 H( g) Br( g) HBr( g) [] I x x [ C] [ E] x 1645 x HBr H Br = [ ] [ ][ ] = ( x 1645) x 1645 x = 5 M [ H]= 5 mol L ( ) ( ) 16 system must be closed temperature is constant forward and reverse rates are ual macroscopic properties are constant can be achieved from either direction concentration of reactants and products are constant

20 LExample: container is initially filled with 1 H ( g ) + I ( g ) HI( ga ) 1For At uilibrium the O concentration is 6 b) [HI] = [H ][I ] 17 a) 1uilibrium system: 3 Consider the following HI For Example: 8 = (1) (5)(1) SO( g ) + O( g ) SO3( g ) SO( g ) + O( g ) SO3( 6 Concentration = H (mol L) 1O 1 A 1 L container is initially filled with 1 mol SO and[i]1 mol 4 3 Consider the following uilibrium: ( marks) At uilibrium the O concentration is 6 mol L Calculate the value of (4 marks) [C] 8 I NF( g ) N F4( g ) 6 8 [E] 18chk t t t Consider (4 marks) For Example:the following: Equilibrium shifts to the right when volume is decreased Describe the changes in 18 HI reaction rates that cause this shift to the right [SO3 ] H I + SO( g ) + O = ( g )( g ) ( g ) SO3( g )( g ) [SO ] [O ] is increased at t 1 1 at t1 and uilibrium is reestablished [I]The temperature 8) (marks = Lcontainer mol H and mol I are added to an empty Initially, [Ca) ] On time t1 and the above graph, sketch the +line representing the [HI] between ) t 3 (1 mark) For Example: At uilibrium, the [I ] = mol L What is the value of? () (6 6 8 [E] = Consider the following: 19 Both forward and reverse rates increase as a result of 1 mark increased concentration For Example: CH 4( g ) + H O SO [ 3 ]increases more than the reverse rate, The forward rate = For Example: 1 mark SO ] [Oshifts so the uilibrium to the right [ ] Initially, See graph above 1 mark 6 mol CH 4, 8 mol H marks H (8) + I HI placed into a 4of minimum L container At u reactions tendtoward a position enthalpy an 3 Chemical = 13 maximum entropy the value of? 6 (1following: ) ( ) 1 (4 marks) 4 Consider mol L [I] the = 7 1 a) What is meant by the term enthalpy? [C] b) Calculate the value of after t ( marks) CH 4( g ) +H O( g ) CO( g ) + 3H ( g ) 4 marks 3 State Le Chatelier s Principle ( marks) 16 [E] For Example: Initially, 6 mol CH 4, 8 mol H O, 8 mol CO and 74 mol H are placed into a 4 L container At uilibrium, the [H ] = mol L What is For Example: Example: HI]? (16) =For the value[of CH 4 HO + 64 = = For Example:[H ][I HI ( )( ) ]] [ = 15 mol L [I]content Enthalpy is a measure of heat H ][I ] [ Le Chatelier s Principle states that when a stress is placed on 131 C] 5 5 [ 3 an Chemical reactions toward a position marks uilibrium system will shiftoftominimum offset thisenthalpy and 1system, ) tendthe ( marks For Example: maximum stress until=entropy a(new is reached [E ] 5)(uilibrium 1) entropy? What +is meant a) WhatCH is= meant by the b) CO CO] [H ](1 mark) [ 3H by the term + termhenthalpy? 4 O = [CH 4 ][HO] 7 18chk 185 [I] 15 mol L marks (75) ()3 = [C] 5 (1) (15 ) 18chk September 7, 1 For Example: For Example: 4 E [ ] = 4 1 mark 3 Enthalpy[CO is a] [measure of heat content Entropy is a measure of randomness 133 H ] = [CH 4 ][HO] 3 marks 75 ) ( )( = 18chk 5September 7, 1 (1) (15)

21 134 H + Br HBr [ I ] [ C] x x + x [ E] x x x HBr x [ H ][ Br ] = ( ) x = [ ] ( x) x x = 17 ( ) = ( ) 1 = 1 [ HBr]= x = 5 M 135 a) + More Zn ( aq) has been added 4 Consider the following: (4 marks) [ IO 3 ] 4 g g N O $ ( ) NO ( ) = Describe Initially, the 6 nature mol of N dynamic uilibrium [ Ions] ( marks) O 4 and mol NO are placed into a L container marks 3 Consider Use calculations the following to determine uilibrium: the direction in which the reaction proceeds in order to reach uilibrium [ Zn + ] CH4( g) + H O $ ( g) CO( g) + 3H( g) For Example: t t For Example: In a dynamic uilibrium, the forward Temperature reaction and reverse! marks reaction continue to proceed at ual rates C, 6 mol 137 [ NO 4]= = 34 mol 68 L1 4 Consider 1 C the following uilibrium: L mol CO [ NO]= = 1 mol L ( g) + Cl $ ( g) COCl( g) Is the forward reaction L in this uilibrium exothermic or endothermic? Explain your [ answer NO ] 1 3 = [ NO 4] = ( ) At uilibrium, the system 4 marks contains (3 mol marks) CO, 1 mol C 4 Consider the following uilibrium: trial = and mol COCl ( 3) in a L container Calculate the val trial < CO ( g) + Cl $ ( g) COCl( g) For Example: At \ uilibrium, The reaction the proceeds system contains to the right mol CO, 1 mol Cl 138 This and ( Deduc uilibrium mol COCl is endothermic in a L container For Example: 1 mark mark for incorrect significant figures ) Calculate the value of (3 marks) Since increases as a result of a temperature increase, [ COCl ] ( uilibrium has shifted to the right = [ CO][ Cl marks ] For Example: ( mol L) = ( mol L)( 1 mol L) 139 [ COCl ] ) 1 ( 1) = = mark CO Cl 1 5 = = [ ][ ] ( mol L) ( mol L)( 1 mol L) ( 1) ( 1 )( 5) = ( )( ) 3 = ) 1 1 mark Deduc mark for incorrect significant figures 1 mark ( )

22 Equilibrium will be shifted to the left, reducing the yield of NH 3 The rate of the reaction would be too low Entropy increases in the forward reaction Enthalpy decreases in the forward reaction Since both favour products, uilibrium will not be attained; or the reaction will go to completion [] I SO + NO Æ NO + SO [ C] [ E] H + I Æ HI [] I x x x Since Trial to the right Trial HI H I = [ ] [ ][ ] x = ( ) ( x)( x) = 1 <, uilibrium is established by proceeding As [ H ] is increased the forward rate increases The forward rate will be greater than the reverse rate, resulting in more HI being produced [ ] is consumed as the shift occurs and the forward rate The H starts to decrease The increasing HI reverse rate [ ] results in an increasing At the new uilibrium the forward and reverse rates will be ual [ NO ][ SO ] = [ SO3][ NO] = ( 414 )( 414 ) ( 59)( 59) = Trial NOCl [ NO] [ Cl ] = ( 56 ) 4 3 = [ ] ( ) ( ) = Since Trial >, the uilibrium will proceed left to reduce the Trial value to

23 [ NO 4] a) b) For Example: Reverse Reaction Initially, 15 mol N and 15 mol O were placed in a 1 L Rate = ( ) Calculate the concentration of all species at uilibrium 63 = mark t Consider the following uilibrium: For Example: c) What stress was N applied at time t? Explain ( marks) ( g) + O( g) Æ NO( g) = a) [ NO ] N b) 65 = 7 = ( 63 ) + O Æ NO Initially, 15 mol N and 15 mol O were placed in a 1 L For Example: = container 65 Calculate NOthe concentration 6 of all species at [] uilibrium I (4 marks) c) Stress: Temperature was decreased C x x 1mark x Explanation: because decreased [ E] 15 x 15 x1mark x For Example: The appearance of the graph is consistent with a temperature shift chk 4 NO May 5, 4 N + O Æ NO [ N][ O] Consider [] I the 15 following uilibrium: 15 ( x) Ô [ C] x x + x 95 Ô3 N ( g) + O( g) Æ NO( g) = mark ( 15 x) Ô [ E] 15 x 15 x x A L container is filled with 15 mol N Ô, 15 mol O and 5 ( xmol ) NO Does the [ NO] increase or decrease as uilibrium is established? 95 = Support your answer with appropriate [ calculations NO ] ( 15 x) (4 marks) = 3 [ N][ O x = ] [ N]= [ O]= 15 x = 14M ( x) For Example: 95 = NO x M1 mark 15 x [ ]= ( ) = b) The Calculate amount of the solid value decreases of at because t 3 the uilibrium Consider the shifts following left uilibrium: (1 mark) [ ] = ( ) = 4 reverse ( ) NO ( x) 3 95 = N O 15 x = [ ] [ ][ ] = ( ) ( ) x= 5 3 Trial = ( )( ) = [ N]= [ O]= 15 x = 14M Trial > so reaction proceeds to the left [ NO]= ( x) = 14 M NO decreases [ ] N( g) + O( g) Æ NO( g) = 9 [ ] + = [ ] 1 1 mark 1 mark 1 marks 1mark 1 mark 1mark 46chk 4