is one then total moles at equilibrium is (A) 1.3 (B) 0.7 (C) 1.6 (D) For reaction HI ½ H 2 value of K c + I 2 2HI. 1 (A) (B) 64 (C) 1 64

Transcription

1 EXERCISE-01 CHEC YOUR GRASP SELECT THE CORRECT ALTERNATIVE (ONLY ONE CORRECT ANSWER) 1. In a reaction PCl 5 PCl + Cl degree of dissociation is 0%. If initial moles of PCl 5 is one then total moles at equilibrium is (A) 1. (B) 0.7 (C) 1.6 (D) 1.0. For reaction HI ½ H + ½ I value of c is 1/8 then value of c for H + I HI. 1 (A) (B) 64 (C) In a equilibrium reaction H + I HI H = 000 calories, which factor favours dissociation of HI :- (D) 8 (A) Low temp. (B) High Pressure (C) High temp. (D) Low pressure. 4. N + H NH If temp. of following equilibrium reaction increase then - (A) Shift Right side (B) Shift left side (C) Unchanged (D) Nothing say. 5. C(s) + H O H + CO by increasing pressure following equilibrium (A) Unaffected (C) Proceed in forward direction (B) Proceed in backward direction (D) Unfixed 6. Unit of equilibrium constant c for following homogenous reaction :- 4NH + 5O 4NO + 6H O is (A) (Conc n ) -1 (B) (Conc n ) +1 (C) (Conc n ) +10 (D) Have no unit 7. Which of the following factor shifted the reaction PCl + Cl PCl 5 at left side. (A) Adding PCl 5 (B) Increase pressure (C) Constant temp. (D) Catalyst. 8. In which of the following process reaction is fastest complete. (A) = 10 (B) = 1 (C) = 10 (D) = At 98 equilibrium constant 1 and of following reaction SO + ½ SO SO + O () The relation between 1 and is O SO (1) (A) 1 = (B) = 1 (C) = 1/ 1 (D) = 1/ In the following reaction PCl 5 PCl + Cl at constant temp. rate of backward reaction is increase by : (A) Inert gas mixed at constant volume (C) Inert gas mixed at constant pressure 1 1. Some gaseous equilibrium are following : CO + H O CO + H (B) Cl gas mixed at constant volume (D) PCl 5 mixed in constant volume. 1 CO + O CO H + O H O then find out the relation between equilibrium constants :- (A) = 1 (B) = ( 1 ) (C) = ( 1 ) ½ (D) = ( 1 / ) ½

2 1. For the equilibrium process x + y xy. If the conc n. of x and y is doubled, then equilibrium constant. (A) Become twice (B) Become half (C) Unchanged (D) Become thrice 1. Two moles of PCl 5 were heated in closed vessel of litre capacity, at equilibrium 40% of PCl 5 was dissociated into PCl and Cl. The value of equilibrium constant is : (A).67 (B).5 (C).67 (D) The reaction A + B C is occur by mixing of moles of A and 1 mole of B in one litre Container. if of B is 1, then C for this reaction is :- (A) 0.1 (B) 0.5 (C) 0.50 (D) Reaction BaO (s) BaO(s) + O ; H = + ve. At equilibrium condition, Pressure of O is depends on :- (A) Increase mass of BaO (C) Increase temp. at Eq m. (B) Increase mass of BaO (D) Increase mass of BaO and BaO both 1 6. Consider the following equilibrium in a closed container N NO. At a fixed temperature, the volume of the reaction container is halved. For this change, which of the following statements held true regarding the equilibrium constant ( p ) and degree of dissociation () :- (A) Neither p nor changes (C) p changes, but does not change 1 7. C(s) + CO CO (B) Both p and - changes (D) p does not change, but - changes According to above reaction, partial Pressure of CO & CO are 4 & 8 respectively then find out p of the above reaction :- (A) 6 (B) (C) 16 (D) 1 8. For the reaction, A+B C + D, c = 9. If A and B are taken in equal amounts, then amount of C at equilibrium is :- (A) 1 (B) 0.5 (C) 0.75 (D) None of these 1 9. At equilibrium 500mL vessel contains 1 5 M of each A, B, C, D. If 0 5M of C and D expelled out then what would be the C :- (A) 1 (B) The following equilibrium are given N + H NH N + O NO H + 1 O H O The equilibrium constant of the reaction (C) 4 9 (D) 5 9 NH + 5 O NO + H O, in terms of 1, and is : (A) 1 (B) 1 (C) 1 (D) 1 1. The reaction A + B C + D is studied in a one litre vessel at 50 C. The initial concentration of A was n and that of B was n. When equilibrium was attained, equilibrium concentration of C was found to the equal to the equilibrium concentration of B. What is the concentration of D at equilibrium : (A) n/ (B) (n 1/) (C) (n n/) (D) n

3 k 1. In a reversible reaction A B, the initial concentration of A and B are a and b in moles per litre and k the equilibrium concentration are (a x) and (b + x) respectively ; express x in terms of k 1, k, a and b : (A) k1a kb k k 1 (B). The value of p for the reaction k1a kb k k 1 H O + Cl O 4HCl + O (C) k1a kb k k 1 (D) k1a kb k k 1 is 0.0 atm at 47 C, when the partial pressure are expressed in atmosphere then the value of C for the same reaction is : (A) (B) (C). 10 (D) The equilibrium constant of the reaction SO + 1 O SO is 4 10 atm 1/. The equilibrium constant of the reaction SO SO + O would be : (A) 50 atm (B) 4 10 atm (C) atm (D) atm 5. When alcohol (C H 5 OH) and acetic acid are mixed together in equimolar ratio at 7 C, % is converted into ester. Then the C for the equilibrium : C H 5 OH () + CH COOH () CH COOC H () + H O () (A) 4 (B) 1/4 (C) 9 (D) 1/9 6. moles each of SO, CO, SO and CO is taken in a one lit. vessel. If C for SO + CO SO + CO is 1/9 then : (A) total no. of moles at equilibrium are less than 8 (B) n (SO ) + n(co ) = 4 (C) [n(so )/n (CO)] < 1 (D) both (B) and (C) 7. An equilibrium mixture in a vessel of capacity 100 litre contain 1 mol N, mol O and mol NO. No. of moles of O to be added so that at new equilibrium the conc. of NO is found to be 0.04 mol/lit : (A) (101/18) (B) (101/9) (C) (0/9) (D) None of these 8. Ammonia gas at 15 atm is introduced in a rigid vessel at 00. At equilibrium the total pressure of the vessel is found to be atm at 00 C. The degree of dissociation of NH will be : (A) 0.6 (B) 0.4 (C) unpredictable (D) none of these 9. The degree of dissociation of SO is at equilibrium pressure P 0 : p for SO SO + O (A) [(P 0 )/(1 ) ] (B) [(P 0 )/( + )(1 ) ] (C) [(P 0 )/(1 ) ] (D) none of these 0. For the reaction CO + H O CO + H at a given temperature the equilibrium amount of CO can be increased by : (A) adding a suitable catalyst (C) decreasing the volume of container 1. For the reaction : PCl 5 PCl + Cl The forward reaction at constant temperature is favoured by (A) introducing an inert gas at constant volume (C) introducing an inert gas at constant pressure (E) introducing PCl 5 at constant volume (B) adding an inert gas (D) increasing the amount of CO (B) introducing chlorine gas at constant volume (D) increasing the volume of the container

4 . Given the following reaction at equilibrium N + H NH. Some inert gas at constant pressure is added to the system. Predict which of the following facts will be affected : (A) more NH is produced (C) no affect on the equilibrium (B) less NH is produced (D) P of the reaction is decreased. For an equilibrium H O (s) H O () which of the following statement is true : (A) the pressure changes do not affect the equilibrium (B) more of ice melts if pressure on the system is increased (C) more of liquid freezes if pressure on the system is increase (D) the pressure changes may increase or decrease the degree of advancement of the reaction depending upon the temperature of the system. 4. When a bottle of cold drink is opened, the gas comes out with a fizze due to : (A) decrease in temperature (B) increase in pressure (C) decrease in pressure suddenly which results in decrease of solubility of CO gas in water (D) none 5. The equilibrium, SO Cl SO + Cl is attained at 5 C in a closed container and an inert gas, helium, is introduced. Which of the following statements are correct : (A) concentrations of SO, Cl and SO Cl are changed (B) no effect on equilibrium (C) concentration of SO is reduced (D) p of reaction is increasing 6. For the reaction H + I HI C = 66.9 at 50 C and C = 50.0 at 448 C. The reaction has : (A) H = +ve (C) H = Zero (B) H = ve (D) H = Not found the signs 7. Variation of log 10 with 1 T is at 45, hence H is : (A) cal (C) cal is shown by the following graph in which straight line (B) cal (D) cal log 10 A 1/T CHEC YOUR GRASP ANSWER EY EXERCISE -1 Q u e Ans. A B C B B B A C C B D C A B C Q u e Ans. D C C A C A A A D B D A B B D Q u e Ans. C,D,E B B C B B B

5 EXERCISE 0 BRAIN TEASERS SELECT THE CORRECT ALTERNATIVES (ONE OR MORE THEN ONE CORRECT ANSWERS) 1. Consider following reaction in equilibrium with equilibrium concentration 0.01 M of every species (I) PCl 5 PCl + Cl (II) HI H + I (III) N + H NH Extent of the reactions taking place is : (A) I > II > III (B) I < II < III (C) II < III < I (D) III < I < II. For the reaction A + B C at a given temperature, c = 9.0. What must be the volume of the flask, if a mixture of.0 mol each of A, B and C exist in equilibrium? (A) 6 L (B) 9 L (C) 6 L (D) None of these. Sulphide ion in alkaline solution reacts with solid sulphur to form polysulphide ions having formulae S, S, S 4-- and so on. The equilibrium constant for the formation of S is 1 ( 1 ) & for the formation of S is 1 ( ), both from S and S. What is the equilibrium constant for the formation of S from S and S? (A) 11 (B) 1 (C) 1 (D) None of these 4. For the following gases equilibrium N NO p is found to be equal to c. This is attained when : (A) 0 C (B) 7 (C) 1 (D) mole N and mol H are placed in a closed container at a pressure of 4 atm. The pressure falls to atm at the same temperature when the following equilibrium is attained (A) N + H NH. The equilibrium constant P for dissociation of NH is : 1 (1.5) atm (B) 0.5 (1.5) atm (C) (1.5) atm (D) atm 0.5 (1.5) 6. One mole of N at 00 is left in a closed container under one atm. It is heated to 600 when 0% by mass of N decomposes to NO. The resultant pressure is : (A) 1. atm (B).4 atm (C).0 atm (D) 1.0 atm 7. For the reaction : HI H + I, the degree of dissociation () of Hl is related to equilibrium constant P by the expression : (A) 1 p (B) 1 p (C) p 1 P (D) p 1 8. The vapour density of N at a certain temperature is 0. What is the % dissociation of N at this temperature : (A) 5.% (B) 106.6% (C) 6.7% (D) None 9. For the reaction PCl 5 PCl + Cl, the forward reaction at constant temperature is favoured by : (A) introducing an inert gas at constant volume (B) introducing chlorine gas at constant volume (C) introducing an inert gas at constant pressure (D) introducing PCl 5 at constant volume p

6 1 0. When N O 5 is heated at temp. T, it dissociates as N O 5 N O + O, C =.5. At the same time N O also decomposes as : N O N O + O. If initially 4.0 moles of N O are taken in 1.0 litre 5 flask and allowed to attain equilibrium, concentration of O was formed to be.5 M. Equilibrium concentration of N O is : (A) 1.0 (B) 1.5 (C).166 (D) Densities of diamond and graphite are.5 and. g/ml. C (diamond) C (graphite) favourable conditions for formation of diamond are : (A) high pressure and low temperature (B) low pressure and high temperature (C) high pressure and high temperature (D) low pressure and low temperature r H = 1.9 kj/mole 1. When NaNO is heated in a closed vessel, oxygen is liberated and NaNO is left behind. At equilibrium: (A) addition of NaNO favours reverse reaction (B) addition of NaNO favours forward reaction (C) increasing temperature favours forward reaction (D) increasing pressure favours reverse reaction 1. The equilibrium SO Cl SO + Cl is attained at 5 C in a closed rigid container when an inert gas, helium is introduced. Which of the following statement is / are correct : (A) concentrations of SO, Cl and SO Cl do not change (B) more chlorine is formed (C) concentration of SO is reduced (D) more SO Cl is formed 1 4. For the gas phase reaction, C H 4 + H C H 6 (H =.7 kcal), carried out in a closed vessel, the equilibrium moles of C H 4 can be increased by : (A) increasing the temperature (B) decreasing the pressure (C) removing some H (D) adding some C H An exothermic reaction is represented by the graph : (A) ln p (B) ln p (C) ln p (D) ln p 1/T 1/T 1 6. The correct relationship between free energy change in a reaction and the corresponding equilibrium constant is : (A) G = RT ln (B) G = RT ln (C) G = RT ln (D) G = RT ln 1 7. The value of G f of gaseous mercury is 1 kj/mole. At what external pressure mercury start boiling 5 C. [R = 8. J/ mole] (A) (B) (C) (D) What is r G (kj/mole) for synthesis of ammonia at 98 at following sets of partial pressure : N + H NH ; r G = kj/mole. [Take R = 8. J/ mole, log = 0. ; log = 0.48] Gas N H NH Pressure (atm) (A) +6.5 (B) 6.5 (C) (D) /T 1/T

7 1 9. In a 7.0 L evacuated chamber, 0.50 mol H and 0.50 mol I react at 47 C. H + I HI. At the given temperature, C = 49 for the reaction. (i) What is the value of p? (A) 7 (B) 49 (C) 4.5 (D) None (ii) What is the total pressure (atm) in the chamber? (A) 8.14 (B) 81.4 (C) 8.1 (D) None (iii) How many moles of the iodine remain unreacted at equilibrium? (iv) (A) 0.88 (B) 0.11 (C) 0.5 (D) 0.15 What is the partial pressure (atm) of HI in the equilibrium mixture? (A) 6.85 (B) 1.77 (C) (D) N + O NO, 1 ; 1 N + 1 O NO, 1 NO N + O, ; NO N + 1 O, 4 Correct relation between 1,, and 4 is : (A) 1 = 1 (B) 1 4 = 1 (C) = 1 (D) None 1. The equation, a = D d (n 1)d (A) A nb/ + nc/ (C) A (n/)b + (n/4)c is correctly matched for : (B) A nb/ + (n/)c (D) A (n/)b + C. Variation of equilibrium constant for the reaction ; A (s) + B absolute temperature T in figure as - n Vs (1/T) : C + D is plotted against n (A) the forward reaction is exothermic (C) the slope of line is proportional to H (E) removing C favours forward reaction 1/T ( n vs 1/T diagram) (B) the forward reaction is endothermic (D) adding 'A' favours forward reaction. The equilibrium of which of the following reactions will not be disturbed by the addition of an inert gas at constant volume? (A) H + I HI (C) CO + H CH OH (B) N NO (D) C(s) + H O CO + H 4. An industrial fuel, 'water gas', which consists of a mixture of H and CO can be made by passing steam over red-hot carbon. The reaction is : C(s) + H O CO + H, H = +11 kj The yield of CO and H at equilibrium would be shifted to the product side by (A) raising the relative pressure of the steam (B) adding hot carbon (C) raising the temperature (D) reducing the volume of the system

8 5. The dissociation of ammonium carbamate may be represented by the equation : NH 4 CO NH (s) NH + CO H 0 for the forward reaction is negative. The equilibrium will shift from right to left if there is (A) a decrease in pressure (B) an increase in temperature (C) an increase in the concentration of ammonia (D) an increase in the concentration of carbon dioxide 6. The percentage of ammonia obtainable, if equilibrium were to be established during the Haber process, is plotted against the operating pressure for two temperatures 400 C and 500 C. Which of the following correctly represents the two graphs? (A) % NH at equilibrium C 500 C 10 0 Pressure/10 kpa (B) % NH at equilibrium C 400 C 10 0 Pressure/10 kpa (C) % NH at equilibrium C 500 C 10 0 Pressure/10 kpa (D) % NH at equilibrium C 500 C 10 0 Pressure/10 kpa BRAIN TEASERS ANSWER EY EXERCISE - Qu e An s. B A A D B B D A C,D D C C,D A A,B,C,D A Qu e ( i) ( ii) ( iii) ( iv) An s. A A D B C B A A,B,C B A,C,E A,B,C,D A,C B,C,D A

9 EXERCISE 0 MISCELLANEOUS TYPE QUESTIONS TRUE / FALSE 1. Van't Hoff's equation gives the quantitative relation between change in value of with change in temperature.. The larger value of indicates that the product is more stable relative to reactants.. The value of equilibrium constant changes with change in the initial concentration of the reactants. 4. Extent of a reaction can always be increased by increasing the temperature. 5. P is related to C as P = C (RT) n. 6. Introduction of inert gas in a gaseous reaction (n g 0) at equilibrium keeping pressure constant has no effect on equilibrium state. 7. For the reaction, N NO, P = C (RT). 8. For a reaction the value of Q greater than indicates that the net reaction is proceeding in backward direction. 9. Solubilities of all solids in water increase with increase in temperature Dissolution of all gases in water is accompained by evolution of heat. [NH 1 1. For the reaction, N + H ] NH, the equilibrium expression may be written as = [N ][H ] 1. For the reaction, CaCO (s) CaO (s) + CO, P = p CO. 1. A catalyst increases the value of the equilibrium constant for a reaction If concentration quotient of reaction is less than, the net reaction is proceeding in the backward direction In case of endothermic reaction, the equilibrium shifts in backward direction on increasing the temperature The value of increases with increase in pressure For the reaction, H + I HI, the equilibrium constant, is dimensionalless The reaction SO + O SO, H = X kj, is favoured by high pressure and high temperature A very high value of indicates that at equilibrium most of the reactants are converted into products. 0. The value of for the reaction, N + H NH, can be increased by applying high pressure or by using a catalyst. FILL IN THE BLANS 1. for the reaction A + B C is This indicates that at equilibrium the concentration of... would be maximum.. The reaction N + O NO Heat, would be favoured by... temperature.. for the reaction X + Y XY is 100 for this reaction XY 1 X + 1 Y would be Compared to for the dissociation, H S H + + HS, then ' for the H + + HS H S would have The equilibrium constant for a reaction decreases with increase in temperature, the reaction must be For the reaction, PCl 5 are related as.... P C 7. For the reaction, N, at equilibrium, increase in pressure shifts the equilibrium in... direction..

10 8. G is related to by the relation Vant Hoff's equation is When the reaction is at equilibrium, the value of G is Dimensions of equilibrium constant, c for the reaction NH N + H, are The value of for a reaction can be changed by changing The law of mass action was proposed by The degree of dissociation of PCl 5 [PCl 5 PCl + Cl ],... with increase in pressure at equilibrium If concentration quotient, Q is greater than C, the net reaction in taking place in... direction The reaction, N + H NH would be favoured by... pressure P is related to C as Solubility of a gas in water... with increase in temperature Introduction of inert gas at constant volume to a gaseous reaction at equilibrium results in formation of... product. 0. The product is more stable than reactants in reaction having.... MATCH THE COLUMN 1. C o l u m n-i C olumn-ii ( Reactions ) (Favourable conditions) (A) Oxidation of nitrogen (p) Addition of inert gas at constant pressure N + O kj NO (B) Dissociation of N (q) Decrease in pressure N kj NO (C) Oxidation of NH (r) Decrease in temperature 4NH + 5O 4NO + 6H O kj (D) Formation of NO (s) Increase in temperature NO + O NO + O + 00 kj. C o l u m n-i Column-II ( R eaction) (If is negligiable w.r.t. 1) (A) (B) (C) (D) X Y + Z (p) = c X Y + Z (q) = c X Y + Z (r) = ( c ) 1/ X Y + Z (s) = c

11 ASSERTION & RE ASON These questions contains, Statement I (assertion) and Statement II (reason). (A) Statement-I is true, Statement-II is true ; Statement-II is correct explanation for Statement-I. (B) Statement-I is true, Statement-II is true ; Statement-II is NOT a correct explanation for statement-i (C) Statement-I is true, Statement-II is false (D) Statement-I is false, Statement-II is true 1. Statement-I : The melting point of ice decreases with increase of pressure. B e c a u s e Statement-II : Ice contracts on melting.. Statement-I : The equilibrium of A B + C is not affected by changing the volume. B e c a u s e Statement-II : c for the reaction does not depend on volume of the container.. Statement-I : For the reaction A B + C, p = 1 atm. If we start with equal moles of all gases at 9 atm of initial pressure, then at equilibrium partial pressure of A increases. B e c a u s e Statement-II : Reaction quotient Q p > p hence equilibrium shifts in backward direction. 4. Statement-I : For a reaction at equilibrium, the Gibb's free energy of reaction is minimum at constant temp. and pressure. B e c a u s e Statement-II : The Gibb's free energy of both reactants and products increases and become equal at equilibrium. 5. Statement-I : Equilibrium constant for the reverse reaction is the inverse of the equilibrium constant for the reaction in the forward direction. B e c a u s e Statement-II : Equilibrium constant depends upon the way in which the reaction is written. 6. Statement-I : For the reaction H + I HI if the volume of vessel is reduced to half of its original volume, equilibrium concentration of all gases will be doubled. B e c a u s e Statement-II : According to Le Chatelier's principle, reaction shifts in a direction that tends to minimized the effect of the stress. 7. Statement-I : For the reaction at certain temperature A + B C there will be no effect by addition of inert gas at constant volume. B e c a u s e Statement-II : Molar concentration of all gases remains constant. 8. Statement-I : The catalyst does not alter the equilibrium constant. B e c a u s e Statement-II : For the catalysed reaction and uncatalysed reaction H remains same and equilibrium constant depends on H.

12 COMPREHENSION BASED QUESTIONS Comprehensi on # 1 On July, 1, 000, the combined tunnel and bridge connecting Denmark and Sweden was officially opened. It consists of a tunnel from Copenhagen to an artificial Island and a bridge from the island to Malmo in Sweden. The major construction materials employed are concrete and steel. This problem deals with chemical reactions relating to production and degradation of such materials. Concrete is produced from a mixture of cement, water, sand and small stones. Cement consists primarly of calcium silicates and calcium aluminates formed by heating and grinding of clay and limestone. In the later steps of cement production may lead to formation of unwanted hemihydrate, CaS. 1 H O. Consider the following reaction : CaS. H O(s) CaS. 1 H O(s) H O The following thermodynamic data apply at 5 C, standard pressure : 1.00 bar : C o m p o u n d H /(kj mol 1 ) (H f ) S /(J 1 mol 1 ) CaS. H O(s) CaS. 1 H O(s) H O Gas constant ; R = 8.14 J mol H for the transformation of 1.00 kg of CaS.H O(s) to CaS. 1 H O(s) is : (A) +446 kj (B) +484 kj (C) 446 kj (D) 484 kj. Equilibrium pressure (in bar) of water vapour in a closed vessel containing CaS. H O(s), CaS (s). 1 H O(s) and H O at 5 C is : (A) bar (B) bar (C) bar (D) bar. Temperature at which the equilibrium water vapour pressure is 1.00 bar. (A) 107 C (B) 80 C (C) 15 C (D) 40 C Comprehensi on # Questions are based on the manufacture of Na CO by Solvay process : In the manufacture of Na CO (s) by Solvay process, NaHCO (s) is decomposed by heating : NaHCO (s) Na CO (s) + CO + H O p = 0. at 100 C H = 16 kj 1. If a sample of NaHCO (s) is brought to a temperature of 100 C in a closed container total gas pressure at equilibrium is : (A) 0.96 atm (B) 0. atm (C) 0.48 atm (D) 0.46 atm

13 . A mixture of 1.00 mol each of NaHCO (s) and Na CO (s) is introduced into a.5 L flask in which P CO of : =.10 atm and P = 0.94 atm.when equilibrium is established at 100 C, then partial pressure HO (A) CO and H O will be greater than their initial pressure (B) CO and H O will be less than their initial pressure (C) CO will be larger and that of H O will be less than their initial pressure (D) H O will be larger and that of CO will be less than their initial pressure MISCELLANEOUS TYPE QUESTION ANSWER EY EXERCISE - Tr ue / False 1. T. T. F 4. F 5. T 6. F 7. T 8. T 9. F 10. T 11. T 1. T 1. F 14. F 15. F 16. F 17. T 18. F 19. T 0. F Fill in the Blanks C. high exothermic 6. P = C (RT) 7. backward 8. G = RT ln 9. log H T T1 1.0R T T1 10. zero 11. mol L 1. temperature 1. Guldberg and Waage 14. decreases 15. backward 16. high 17. P = C (RT) n 18. decreases 19. same amount of 0. large value of Match the Column 1. A - (s), B - (p,q,s), C - (p,q,r), D - (r). A - (p), B - (s), C - (q), D - (r) Asserti on - Reason Questions 1. A. D. A 4. C 5. A 6. B 7. A 8. A Comprehension Based Que st ions Comprehension #1 : 1. B. C. A Comprehension # : 1. A. B

14 EXERCISE 04 [A] CONCEPTUAL SUBJECTIVE EXERCISE Reaction quotient and equillibrium constant 1. The initial concentration or pressure of reactants and products are given for each of the following systems. Calculate the reaction quotient and determine the directions in which each system will shift to reach equilibrium. (a) NH N + H = 17 [NH ] = 0.0 M ; [N ] = 1.00 M ; [H ] = 1.00 M (b) NH N + H p = atm Initial pressure : NH =.0 atm ; N =.0 atm ; H = 1.0 atm (c) SO SO + O = 0.0 atm [SO ] = 0.00 M ; [SO ] = 1.00 M ; [O ] = 1.00 M (d) SO SO + O p = 16.5 atm (e) Initial pressure : SO = 1.0 atm ; SO = 1.0 atm ; O = 1.0 atm NO + Cl NOCl = [NO] = 1.00 M ; [Cl ] = 1.00 M ; [NOCl] = 0 M. Among the solubility rules, the statement that all chlorides are soluble except Hg Cl, AgCl, PbCl, and CuCl. (a) (b) Write the expression for the equilibrium constant for the reaction represented by the equation AgCl (s) Ag + (aq) + Cl (aq) Is greater than 1, less than 1, or about equal to 1? Explain your answer. Write the expression for the equilibrium constant for the reaction represented by the equation Pb + (aq) + Cl (aq) PbCl (s) Is greater than 1, less than 1, or about equal to 1? Explain your answer.. Benzene is one of the compounds used as octane enhancers in unleaded gasoline. It is manufactured by the catalytic conversion of acetylene to benzene. C H C 6 H 6 Would this reaction be most useful commercially if were about 0.01, about 1, or about 10? Explain your answer. 4. For which of the following reactions will the equilibrium mixture contain an appreciable concentration of both reactants and products? (a) (b) Cl Cl ; c = Cl + NO NOCl ; c = (c) Cl + NO NO Cl ; c = The value of c for the reaction O O is at 5 C. Do you expect pure air at 5 C to contain much O (ozone) when O and O are in equilibrium? If the equilibrium concentration of O in air at 5 C is 8 10 M, what is the equilibrium concentration of O.

15 6. At 1400, c =.5 10 for the reaction CH 4 + H S CS + 4H. A 10.0 L reaction vessel at 1400 contains.0 mol of CH 4,.0 mol of CS,.0 mol of H and 4.0 mol of H S. Is this reaction mixture at equilibrium? If not, in which direction does the reaction proceed to reach equilibrium? 7. An equilibrium mixture of N, H and NH at 700 contains 0.06 M N and 0.15 M H. At this temperature, c for the reaction N + H NH is 0.9. What is the concentration of NH? 8. The air pollutant NO is produced in automobile engines from the high temperature reaction N + O NO ; c = at 00. If the initial concentrations of N and O at 00 are both 1.40 M, what are the concentration of NO, N and O when the reaction mixture reaches equilibrium? 9. At a certain temperature, the reaction PCl 5 PCl + Cl has an equilibrium constant c = Calculate the equilibrium concentrations of PCl 5, PCl and Cl if only PCl 5 is present initially, at a concentration of M At 700, p = for the reaction ClF ClF + F. Calculate the equilibrium partial pressure of ClF, ClF and F if only ClF is present initially ; at a partial pressure of 1.47 atm. Homogeneous equi libria degree of dissociat ion, vapour densit y a nd equi librium consta nt 1 1. The degree of dissociation of N into NO at 1.5 atmosphere and 40 C is 0.5. Calculate its p at 40 C. Also report degree of dissociation at 10 atmospheric pressure at same temperature. 1. At 46 C, p for the reaction N NO is atm. Compute the percent dissociation of N at 46 C at a total pressure of 80 Torr. 1. When 6.8 g N is introduced into a litre flask at 7 C. The following equilibrium reaction occurs : N NO ; p = atm. (a) (b) (c) Calculate c of the equilibrium reaction. What are the number of moles of N and NO at equilibrium? What is the total gas pressure in the flask at equilibrium? (d) What is the percent dissociation of N? 1 4. At some temperature and under a pressure of 4 atm, PCl 5 is 10% dissociated. Calculate the pressure at which PCl 5 will be 0% dissociated, temperature remaining same In a mixture of N and H in the ratio of 1 : at 64 atmospheric pressure and 00 C, the percentage of ammonia under equilibrium is. by volume. Calculate the equilibrium constant of the reaction using the equation. N + H NH 1 6. The system N NO maintained in a closed vessel at 60 C & pressure of 5 atm has an average (i.e. observed) molecular weight of 69, calculate p. At what pressure at the same temperature would the observed molecular weight be (0/)? 1 7. The vapour density of N at a certain temperature is 0. Calculate the percentage dissociation of N at this temperature. N NO In the esterification C H 5 OH () + CH COOH () CH COOC H 5 () + H O () an equimolar mixture of alcohol and acid taken initially yields under equilibrium, the water with mole fraction = 0.. Calculate the equilibrium constant.

16 Hetrogeneous equi librium 1 9. Solid Ammonium carbamate dissociates as : NH COONH 4 (s) NH + CO. In a closed vessel solid ammonium carbamate is in equilibrium with its dissociation products. At equilibrium, ammonia is added such that the partial pressure of NH at new equilibrium now equals the original total pressure. Calculate the ratio of total pressure at new equilibrium to that of original total pressure. 0. A sample of CaCO (s) is introduced into a sealed container of volume 0.81 litre & heated to 1000 until equilibrium is reached. The equilibrium constant for the reaction CaCO (s) CaO (s) + CO is 4 10 atm at this temperature. Calculate the mass of CaO present at equilibrium. 1. Anhydrous calcium chloride is often used as a dessicant. In the presence of excess of CaCl, the amount of the water taken up is governed by p = for the following reaction at room temperature, CaCl (s) + 6H O CaCl. 6H O (s). What is the equilibrium vapour pressure of water in a closed vessel that contains CaCl (s)?. 0.0 grams of CaCO (s) were placed in a closed vessel, heated & maintained at 77 C under equilibrium CaCO (s) CaO (s) + CO and it is found that 75% of CaCO was decomposed. What is the value of p? The volume of the container was 15 litres. Changes in concentration at equilibrium Le Chatelier' s principle. Suggest four ways in which the concentration of hydrazine, N H 4, could be increased in an equilibrium described by the equation N + H N H 4 H = 95 kj 4. How will an increase in temperature and increase in pressure affect each of the following equilibria? (a) (b) (c) (d) NH N + H N + O NO O O CaO (s) + CO CaCO (s) H = 9 kj H = 181 kj H = 85 kj H = 176 kj 5. (a) Water gas, a mixture of H and CO, is an important industrial fuel produced by the reaction of steam with red-hot coke,essentially pure carbon. Write the expression for the equilibrium constant for the reversible reaction. C (s) + H O CO + H H = 11.0 kj (b) Assume that equilibrium has been established and predict how the concentration of each reactant and product will differ at a new equilibrium if (1) more C is added. () H O is removed. () CO is added (4) the pressure on the system is increased. (5) the temperature of the system is increased. 6. Ammonia is weak base that reacts with water according to the equation NH (aq) + H O (l) NH 4 + (aq) + OH (aq) Will any of the following increase the percent of ammonia that is converted to the ammonium ion in water? (a) Addition of NaOH. (b) (c) Addition of HCl. Addition of NH 4 Cl. 7. Suggest two ways in which equilibrium concentration of Ag + can be reduced in a solution of Na +, Cl, Ag + and NO, in contact with solid AgCl. Na + (aq) + Cl (aq) + Ag + (aq) + NO (aq) AgCl (s) + Na + (aq) + NO (aq) H = 65.9 kj

17 inetics and equilibrium constant 8. Consider a general single-step reaction of the type A + B C. Show that the equilibrium constant is equal to the ratio of the rate constant for the forward and reverse reaction, c = f / r. 9. Consider the reaction of chloromethane with OH in aqueous solution CH Cl (aq) + OH (aq) k f CH OH (aq) + Cl kr (aq) At 5 C, the rate constant for the forward reaction is M 1 s 1, and the equilibrium constant c is Calculate the rate constant for the reverse reaction at 5 C. 0. The progress of the reaction A nb with time, is presented in figure, Determine (i) the value of n (ii) the equilibrium constant. (iii) the initial rate of conversion of A Time/Hour Temperature dependence of equi librium consta nt 1. Listed in the table are forward and reverse rate constants for the reaction NO N + O Temperature () k f (M 1 s 1 ) k r (M 1 s 1 ) Is the reaction endothermic or exothermic?. Rate of disappearance of the reactant A at two different temperature is given by A B d[a] dt d[a] dt = ( 10 S 1 ) [A] 4 10 S 1 [B] ; 00 = (4 10 S 1 ) [A] S 1 [B] ; 400 Calculate heat of reaction in the given temperature range. When equilibrium is set up.. The P for reaction A + B C + D is 1.4 at 60 C and 6.64 at 100 C. Determine the free energy change of this reaction at each temperature and H for the reaction over this range of temperature? Equi librium expre ssions a nd equi librium consta nt s 4. If c = at 1000 for the reaction N + O NO, what is c at 1000 for the reaction NO N + O? 5. A sample of HI ( mol) was placed in an empty.00 L container at After equilibrium was reached, the concentration of I was M. Calculate the value of c at 1000 for the reaction H + I HI. 6. The vapour pressure of water at 5 C is 0.01 atm. Calculate the values of p and c at 5 C for the equilibrium H O () H O.

18 7. For each of the following equilibria, write the equilibrium constant expression for c. Where appropriate, also write the equilibrium constant expression for p. (a) (b) (c) (d) Fe O (s) + CO Fe () + CO 4Fe (s) + O Fe O (s) BaS (s) BaO (s) + SO BaS (s) Ba + (aq) + S (aq) General problems 8. When 0.5 mol of N is placed in a 4.00 L reaction vessel and heated at 400, 79. % of the N decomposes to NO. Calculate c and p at 400 for the reaction N NO. 9. At 100, then value of c for the reaction C(s) + H O CO + H is Calculate equilibrium concentrations of H O, CO and H in the reaction mixture obtained by heating 6.0 mole of steam and an excess of solid carbon in a 5.0 L container. What is the molar composition of the equilibrium mixture? 4 0. When 1.0 mol of PCl 5 is introduced into a 5.0 L container at 500, 78.5 % of the PCl 5 dissociates to given an equilibrium mixture of PCl 5, PCl and Cl. PCl 5 PCl + Cl (a) Calculate the values of c and p. (b) If the initial concentrations in a particular mixture of reactants and products are [PCl 5 ] = 0.5 M, [PCl ] = 0.15 M, and [Cl ] = 0.6 M, in which direction does the reaction proceed to reach equilibrium? What are the concentrations when the mixture reaches equilibrium? T hermo dynamic a nd equi librium consta nt D-Glucose undergoes mutarotation to -D-Glucose in aqueous solution. If at 98 there is 60% conversion. Calculate G of the reaction. -D-Glucose -D-Glucose 4. For the reaction at 98 A + B C + D H = 9.8 kcal ; S = 0.1 kcal/ Calculate G and. 4. The equilibrium constant of the reaction C H 6 C H 4 + C 4 H 8 is found to fit the expression n = T Calculate the standard reaction enthalpy and entropy at PCl 5 dissociates according to the reaction PCl 5 PCl + Cl. At 5, p =1.78 atm. Find the density of the equilibrium mixture at a total pressure of 1 atm The following data for the equilibrium composition of the reaction Na Na at 1.01 MP a pressure and have been obtained. mass % Na (monomer gas) = 71. mass % Na (dimer gas) = 8.7 Calculate the equilibrium constant p.

19 4 6. A certain gas A polymerizes to a small extent at a given temperature & pressure, na A n. Show that the gas obeys the approx equation PV RT = (n 1) c 1 n 1 V where = A n c n A container. Assume that initially one mole of A was taken in the container. & V is the volume of the 4 7. When 1 mole of A is introduced in a closed rigid 1 litre vessel maintained at constant temperature the following equilibria are established. A B + C : C1 C D + B : C The pressure at equilibrium is twice the initial pressure. Calculate the value of C C1 if [C] eq 1 [B] 5 eq

20 CONCEPTUAL SUBJECTIVE EXERCISE ANSWER EY E X E RC ISE - 4( A) 1. (a) 5, shifts left, (b) 0., shifts right, (c), shifts left, (d) 1, shifts right, (e) 0, shifts right. (a) = [Ag + ] [Cl ] is less than 1. AgCl is insoluble thus the concentration of ions are much less than 1 M (b) = 1/[Pb + ] [Cl ] is greater than one because PbCl is insoluble and formation of the solid will reduce the concentration of ions to a low level.. about c 5. ~ 9 10 mol/l 6. The reaction is not in equilibrium because Q c > c. The reaction will proceed from right to left to reach equilibrium M 8. [NO] = M, [N ] = [O ] = 1.7 M 9. [PCl ] = [Cl ] = M, [PCl 5 ] = M 10. P CIF = P F = 0.89 atm, P ClF = 1.08 atm 11. P = 0.4, ~ % 1. (a) mol L 1 ; (b) n (N ) = 0.74 mol ; n (NO ) = 0.05 mol ; (c) atm (d) 6.44% atm 15. P = atm 16. p =.5 atm, P = 15 atm % 18. = / mg 1. P H O = atm atm. add N, add H, increase the pressure, heat the reaction 4. (a) shift right, shift left, (b) shift right, no effect, (c) shift left, shift left, (d) shift left, shift right 5. (a) = [CO][H ] / [H O] ; (b) in each of the following cases the mass of carbon will change, but its concentration (activity) will not change. 1. [H O] no change, [CO] no change, [H ] no change ;. [H O] decrease, [CO] decrease, [H ] decrease ;. [H O] increase, [CO] increase, [H ] decrease ; 4. [H O] increase, [CO] decrease, [H ] decrease ; 5. [H O] decrease, [CO] increase, [H ] increase ; 6. b 7. Add NaCl or some other salt that produces Cl in the solution. Cool the solution k 8. k f [A][B] = k r [C] ; f k r [C] k c (i) ; (ii) 1. mol/l ; (iii) 0.1 moles/hr [A ][B] 1. The reaction is exothermic kj. 810 J/mol ; 587 J/mol and 41. kj/mol p = 0.01 atm, c = [CO ] 7. (a) c = [CO] P, p = P CO CO 1 1, (b) c =, [O ] p = (P ) O ; (c) c = [SO ], p = P SO (d) c = [Ba + ] [S ] 8. c = 1.51, p = [CO] = [H ] = 0.18 M ; [H O] = 1.0 M 40. (a) c = 0.57 and p =.5 ; (b) to the right, [PCl 5 ] = 0.65 M ; [PCl ] = 0.85 M ; [Cl ] = 0.75 M kj/mol 4. G = 0 ; = 1 4. H = 9.04 kj/mol ; S = 8.64 J / mol g/l 45. P Na = 0.84 M Pa, P Na = M Pa, k P = To be proved 47. 4

21 EXERCISE 04 [B] mole of CO taken in a.5 litre flask is maintained at 750 along with a catalyst so that the following reaction can take place ; CO + H CH OH. Hydrogen is introduced untill the total pressure of the system is 8.5 atm at equilibrium and 0.08 mole of methanol is formed. Calculate : (i) p & c ; (ii) the final pressure if the same amount of CO and H as before are used, but with no catalyst so that the reaction does not take place.. In a vessel, two equilibrium are simultaneously established at the same temperature as follows : N + H NH...(i) N + H N H 4...(ii) Initially the vessel contains N and H in the molar ratio of 9 : 1. The equilibrium pressure is 7P 0, in which pressure due to ammonia is P 0 and due to hydrogen is P 0. Find the values of equilibrium constant ( P 's) for both the reactions.. The decomposition of solid ammonium carbamete, (NH 4 )(NH CO ), to gaseous ammonia and carbon dioxide is an endothermic reaction. (NH 4 ) (NH CO ) (s) NH + CO (a) When solid (NH 4 ) (NH CO ) is introduced into an evacuated flask at 5 C, the total pressure of gas at (b) equilibrium is atm. What is the value of p at 5 C? Given that the decomposition reaction is at equilibrium, how would the following changes affect the total quantity of NH in the flask once equilibrium is re-established? (i) Adding CO (ii) Adding (NH 4 ) (NH CO ) (iii) Removing CO (iv) Increasing the total volume (v) (vi) Adding neon Increasing the temperature 4. A container contains three gases. A, B and C in equilibrium A B + C At equilibrium the concentration of A was M, and of B was 4 M. On doubling the volume of container, the new equilibrium concentration of B was M. Calculate C and initial equilibrium concentration of C. 5. The density of an equilibrium mixture of N and NO at 1 atm and 46 is 1.8 g/l. Calculate C for the reaction. N NO 6. At 90 C, the following equilibrium is established : H + S(s) H S p = If 0. mol of hydrogen and 1.0 mol of sulphur are heated to 90 C in a 1.0 litre vessel, what will be the partial pressure of H S at equilibrium? 7. At 817 C, p for the reaction between pure CO and excess hot graphite to form CO is 10 atm. (a) What is the analysis of the gases at equilibrium at 817 C & a total pressure of 4.0 atm? What is the partial pressure of CO at equilibrium? (b) At what total pressure will the gas mixture analyze 6%, CO by volume? 8. For the reaction N NO, equilibrium mixture contains NO at P = 1.1 atm & N at P = 0.8 atm at 50. The volume of the container is doubled. Calculate the equilibrium pressures of the two gases when the system reaches new equilibrium. BRAIN STORMING SUBJECTIVE EXERCISE

22 9. The degree of dissociation of HI at a particular temperature is 0.8. Find the volume of 1.5 M sodium thiosulphate solution required to react completely with the iodine present at equilibrium in acidic conditions, when 0.15 mol each of H and I are heated at 440 in a closed vessel of capacity.0 L A mixture of hydrogen & iodine in the mole ratio 1.5 : 1 is maintained at 450 C. After the attainment of equilibrium H + I HI, it is found on analysis that the mole ratio of I to HI is 1 : 18. Calculate the equilibrium constant & the number of moles of each species present under equilibrium, if initially, 17 g of iodine were taken The equilibrium constant for the reaction CO + H O CO + H is 7. at 450 C & 1 atm pressure. The initially concentration of water gas [CO & H in equimolar ratio] & steam are moles & 5 moles respectively. Find the number of moles of CO, H, CO & H O (vapour) at equilibrium. 1. At 100 C, the following equilibrium is established between chlorine atoms & molecule. Cl Cl The composition of equilibrium mixture may be determined by measuring the rate of effusion of the mixture through a pin hold. It is found that at 100 C and 1 atm pressure the mixture effuses 1.16 times as fast as krypton effuses under the same condition. Calculate the equilibrium constant c. 1. Two solids X and Y dissociate into gaseous products at a certain temperature as follows : X(s) A + C, and Y(s) B + C. At a given temperature, pressure over excess solid X is 40 mm and total pressure over solid Y is 60 mm. Calculate : (a) the values of p for two reactions (in mm) (b) the ratio of moles of A and B in the vapour state over a mixture of X and Y. (c) the total pressure of gases over a mixture of X and Y SO decomposes at a temperature of 1000 and at a total pressure of 1.64 atm. At equilibrium, the density of mixture is found to be 1.8 g/l in a vessel of 90 litres. Find the degree of dissociation of SO for SO SO + 1/O The density of an equilibrium mixture of N and NO at 101. P a is.6 g dm at 88 and 1.84 g dm at 48. What is the heat of the reaction for N NO The equilibrium constant for the following reaction at 195. H O H + O 1 = CO CO + O = Calculate the value of for the reaction : H + CO CO + H O 1 7. A saturated solution of iodine in water contains 0. g I /L. More than this can dissolve in a I solution because of the equilibrium : I (aq) + I (aq) I (aq). A 0.10 M I solution (0.10 MI ) actually dissolves 1.5 g of iodine/l, most of which is converted to I. Assuming that the concentration of I in all saturated solutions is the same, calculate the equilibrium constant for the above reaction. What is the effect of adding water to a clear saturated of I in the I solution? 1 8. A mixture of N & H are in equilibrium at 600 at a total pressure of 80 atm. If the initial ratio of N and H are : 1 and at equilibrium NH is 10% by volume, calculate P of reaction at given temperature G (98 ) for the reaction 1/N + H 1 NH is 16.5 kj mol 1. Find the equilibrium constant ( 1 ) at 5 C. What will be the equilibrium constants and for the following reactions : N + H NH NH 1/ N + / H 0. When NO & NO are mixed, the following equilibria are readily obtained ; NO N p = 6.8 atm 1 NO + NO N O p =? In an experiment when NO & NO are mixed in the ratio of 1 :, the total final pressure was 5.05 atm & the partial pressure of N was 1.7 atm. Calculate : (a) the equilibrium partial pressure of NO. (b) p for NO + NO N O

23 1. Solid NH 4 I on rapid heating in a closed vessel at 57 C develops a constant pressure of 75 mm Hg owing to partial decomposition of NH 4 I into NH and HI but the pressure gradually increases further (when the excess solid residue remains in the vessel) owing to the dissociation of HI. Calculate the final pressure developed at equilibrium. NH 4 I(s) NH + HI HI H + I, c = at 57 C. For the reaction SO + 1/O SO H 98 = 98. kj/mole, S 98 = 95.0 J//mole. Find the p for this reaction at 98.. Given are the following standard free energies of formation at 98. CO CO H O H O(l) f G /kj mole (a) Find r G and the standard equilibrium constant p 0 at 98 for the reaction CO + H O CO + H (b) If CO, CO and H are mixed so that the partial pressure of each is kpa and the mixture is brought into contact with excess of liquid water, what will be the partial pressure of each gas when equilibrium is attained at 98. The volume available to the gases is constant. 4. For the reaction C H 6 C H 4 + H p 0 is 0.05 and r G is.84 kj mol 1 at 900. If an initial mixture comprising 0 mol of C H 6 and 80 mol of N (inert) is passed over a dehydrogenation catalyst at 900, what is the equilibrium percentage composition of the effluent gas mixture? The total pressure is kept at 0.5 bar. Given : r S = J 1 mol 1 at 00. Calculate r G at 00. (Assume r C p = 0). 1. (i) k C = mol lit, k P = 0.05 atm (ii) P = 1.48 atm. BRAIN STORMING SUBJECTIVE EXERCISE ANSWER EY EXERCI SE -4 ( B ) 1, P P1 0P0 0P 0. (a) (b) (i) decrease (ii) no change (iii) increase (iv) increase (v) no change (vi) increase atm 7. (i) p(co ) = 0.98 atm (ii) P Total = 0.68atm 8. P NO = 0.64 atm, P N O 4 = atm 9. V = 144 ml 10. k C = 54, n HI = 0.9 mol, n I = 0.05 mol, n H 11. n CO = 0.98, n H = 1.98, n CO = 0.06, n HO = (a) 400 mm, 900 mm (b) 4 : 9 (c) 7.11 mmhg 14. = r H = kj mol k = mol 17. = 707. backward reaction is favoured = 779.4, = ; = (a) 1.05 atm (b).4 atm mmhg. P = atm 1/. (a) G = 8.6 kj/mole (b) P CO = 0.44 kpa, P HO =.16 kpa, P CO = 0. kpa, P = kj/mol

24 EXERCISE - 05 [A] JEE-[MAINS] : PREVIOUS YEAR QUESTIONS 1. Reaction CO + 1 O CO. The value of P c is - [AIE EE - 00 ] (A) RT 1 (B) RT (C) 1 RT (D) RT. One of the following equilibrium is not affected by change in volume of the flask - [AIE EE - 00 ] (A) PCl 5 PCl + Cl (B) N + H NH (C) N + O NO (D) SO Cl SO + Cl. For the reaction equilibrium, N NO the concentration of N and NO at equilibrium are and mol L 1 respectively. The value of C for the reaction is- [AIE EE - 00 ] (A) 10 mol L 1 (B) 10 mol L 1 (C). 10 mol L 1 (D) 10 1 mol L 1 4. Consider the reaction equilibrium [AIE EE - 00 ] SO +O SO ; H = 198 kj On the basis of Le-Chatelier's principle, the condition favourable for the forward reaction is - (A) Lowering the temperature and increasing the pressure (B) Any value of temperature as well as pressure (C) Lowering of temperature as well as pressure (D) Increasing temperature as well as pressure 5. What is the equilibrium expression for the reaction P 4(s) + 5O P 4 O 10(s)? [AIE EE ] (A) C = [P 4 O 10 ] / [P 4 ] [O ] 5 (B) C = [P 4 O 10 ] / 5 [P 4 ] [O ] (C) C = [O ] 5 (D) C = 1 / [O ] 5 6. For the reaction CO + Cl COCl the P C is equal to - [AIE EE ] (A) RT 1 (B) RT (C) RT (D) The equilibrium constant for the reaction N + O NO at temperature T is The value of C for the reaction NO 1 1 N + O [AIE EE ] (A).5 10 (B) 50 (C) (D) For the reaction NO NO + O, ( c = at 184 C) (R = 0.81 kj(mol.)) When p and k c are compared at 184 C it is found that [AIE EE ] (A) p is less than c (B) p is greater than c (C) Whether p is greater than, less than or equal to c depends upon the total gas pressure (D) p = c 9. The exothermic formation of ClF is represented by the equation [AIE EE ] Cl + F ClF ; H r = 9 kj Which of the following will increase the quantity of ClF in an equilibrium mixture of Cl, F and ClF? (A) Removing Cl (B) Increasing the temperature (C) Adding F (D) Increasing the volume of the container

25 1 0. A schematic plot of n eq verus inverse of temperature for a reaction is shown below. The reaction must be (A) endothermic (B) exothermic (C) highly spontaneous at ordinary temperature (D) one with negligible enthalpy change n 6.0 eq /T ( 1 ).0 10 [AIE EE ] 1 1. Phosphorus pentachloride dissociates as follows, in a closed reaction vessel, [AIE EE ] PCl 5 PCl + Cl If total pressure at equilibrium of the reaction mixture is P and degree of dissociation of PCl 5 is x, the partial pressure of PCl will be- (A) x 1 x x P (B) x 1 x x P (C) P (D) P 1 x x 1 1. The equilibrium constant for the reaction SO SO + 1 O is C = The value of C for the reaction [AIE EE ] SO + O SO will be (A) (B) (C) (D) The equlibrium constants p and 1 p for the reaction X Y and Z P + Q, respectively are in the ratio of 1 : 9. If the degree of dissociation of X and Z be equal then the ratio of total pressure at these equilibria is [AIE EE ] (A) 1 : 6 (B) 1 : 1 (C) 1 : (D) 1 : A vessel at 1000 contains CO with a pressure of 0.5 atm. Some of the CO is converted into CO on the addition of graphite. If the total pressure at equilibrium is 0.8 atm, the value of is :- (A) 0. atm (B) 0.18 atm (C) 1.8 atm (D) atm [AIE EE ] 1 5. The equilibrium constant ( C ) for the reaction N + O NO at temperature T is The value of C for the reaction. NO 1 N + 1 O at the same temperature is :- (A) 50.0 (B) 0.0 (C).5 10 (D) [AIE EE - 01 ] JEE-[MAIN] : PREVIOUS YEAR QUESTIONS ANSWER EY EXERCISE -5[A] Q u e A n s C C A A D A B B C B D D A C A