SOLVED QUESTIONS 1 / 2. in a closed container at equilibrium. What would be the effect of addition of CaCO 3 on the equilibrium concentration of CO 2?

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1 SOLVED QUESTIONS Multile Choie Questions. and are the veloity onstants of forward and bakward reations. The equilibrium onstant k of the reation is (A) (B) (C) (D). Whih of the following reations will be favoured at low ressure? (A) (C) N O NO (B) H I HI 5 PCl PCl Cl (D) N H NH. For the reation, A B C D, if ative mass of A is ket onstant and ative mass of B is triled, the rate of reation will beome (A) three times (C) eight times 4. The rate of for the reation: CO( g ) O ( g ) CO ( g ) is (A) (B) six times (D) nine times (B) RT (C) RT / (D) RT / 5. Consider the reation, CaCO ( s ) CaO( s ) CO ( g ) in a losed ontainer at equilibrium. What would be the effet of addition of CaCO on the equilibrium onentration of CO? (A) Inreases (C) Dereases (B) Unreditable (D) Remains unaffeted 6. For the reation, PCl 5(g) PCl (g) Cl (g), the forward reation at onstant temerature is favoured by (A) introduing an inert gas at onstant volume (B) introduing PCl (g) at onstant volume (C) introduing PCl 5 (g) at onstant volume (D) introduing Cl (g) at onstant volume 7. A liquid is in equilibrium with its vaour at its boiling oint. On an average, the moleules in the two hases have equal (A) intermoleules fores (B) otential energy (C) kineti energy (D) both kineti energy and otential energy 8. The unit of equilibrium onstant for the reversible reation

2 H I HI is (A) Lmol (B) L mol (C) moll 9. If and are the equilibrium onstants of the equilibrium (i) and (ii) resetively, what is the relationshi between the two onstants? (i) SO ( g ) O ( g ) SO ( g ); (ii) SO ( g ) SO ( g ) O ( g ); (A) (C) (B) (D) = 0. It is found that equilibrium onstant inrease by a fator of four when the temerature is inreased from 5 C to 40 C. The value of H is (A) 5.46 kj (B) 7.67 kj (C) 89.4 kj (D) 7.67 kj. An examle of reversible reation is (A) Pb(NO ) (aq) + NaI (aq) (B) AgNO (aq) + NaCl (aq) (C) Na(s) + H O(l) (D) NO (aq) + NaCl (aq) PbI (s) + NaNO (aq) AgCl (s) + NaNO (aq) NaOH (aq) + H (g) Cl (aq) + NaNO (aq). Solubility of a substane whih dissolves with derease in volume and absortion of (A) low temerature and low ressure (B) low temerature and high ressure (C) high temerature and high ressure (D) high temerature and low ressure. If ressure is inreased on the equilibrium, Ie Water Whih of the following ours? (A) More of the ie melts (B) More of the ie is formed (C) There is no hange in the amount of ie and water (D) Some water gets vaourized 4. For whih of the following reation =? (A) NOCl(g) NO(g) + Cl (g) (B) N (g) + H (g) (C) H (g) + Cl (g) (D) PCl (g) + Cl (g) NH (g) HCl(g) PCl 5 (g) 5. For the hemial reation X(g) + Y(g) X Y(g), the amount of X Y at equilibrium is affeted by

3 (A) temerature and ressure (C) ressure only (B) temerature only (D) temerature, ressure and atalyst 6. The equilibrium of the reation, N (g) + H (g) NH (g) will shift to rodut side when (A) (C) Q = (B) Q (D) Q = 7. In a reation A+B A B, the reatant (A) will disaear at (A) half the rate at whih B will derease (B) the same rate at whih B will derease (C) the same rate at whih A B will form (D) twie the rate at whih B will derease 8. The equilibrium, SO (g) + O (g) SO (g) shifts forward if (A) a atalyst is used (B) small amount of reatants are used (C) an adsorbent is used to removed SO as soon as it is formed 9. A ten fold inrease in ressure on the reation, N (g) + H (g) NH (g) at equilibrium results in in, (A) ten fold inrease (C) no hange (B) ten fold derease (D) 4 fold derease 9 0. One mole eah of A and B and moles eah of C and D are laed in litre flask, if equilibrium onstant is.5 for A + B C + D, equilibrium onstant of A and C will be in the ratio (A) : (B) : (C) : (D) :. For the given equilibrium L(g) M(g) The f = mole/litre/seonds and b = 0 litre/mole/seonds the equilibrium onentration of M is (A) 0. M (C) 0.8 M (B) 0. M (D) an t be alulated. One mole eah of CH COH and CH CH OH are heated in resene of little on. H SO4 so as to establish the following equilibrium, CH CO H CH CH OH CH CO CH CH H O The moles of CH COCH CH formed at equilibrium is (A) mol (B) mol (C) mol (D) mol. 4 ml of HI are rodued from the reation of 5 ml of H and 7. ml of I vaour at 444C. The equilibrium onstant for the reation,

4 H I HI at 444C is (A) 7.5 (B) (C) (D) 57.5 Aording to Avogadro s law, at onstant temerature and ressure, v n. Thus, x = 4 x = Volume of H at equilibrium = a x 5 ml Volume of I at equilibrium = ml The equilibrium onstant for a reation, A B C D, is to be (A) exothermi (C) unreditable 0 at 98 and.0 at 7. The reation is exeted (B) endothermi (D) neither exothermi nor endothermi is inreased on inreasing temerature. This shows that forward reation is favoured by inrease in temerature. Thus, forward reation should be endothermi. 5. In what manner will inrease of ressure affet the following equation? C( s ) H O( g ) CO( g ) H ( g ) (A) Shift in the forward diretion (B) Shift in the reverse diretion (C) Inrease in the yield of H (D) No effet 6. The value for a reation is 0.9 atm at 00. The value of the reation is (A) 0.9 (B) (C) (D) an t be alulated 7. A ylinder fitted with movable iston ontains liquid water in equilibrium with water vaour at 5 C. Whih oeration would result in a derease in the equilibrium vaour ressure? (A) Moving the iston downwards by a short distane (B) Removing a small amount of vaour (C) Removing a small amount of liquid water (D) Dissolving salt in the water. Addition of salt lower the vaour ressure. 8. For A + B C + X, the favourable onditions to obtain maximum yield of B will be (A) low ressure and low temerature (B) low ressure and high temerature (C) high ressure and high temerature (D) high ressure and high temerature 9. In the reation, N + H NH + X kal, one mole of N reats with three moles of H. At equilibrium, the value of (degree of dissoiation) is aroximately (P= ressure at equilibrium). P 7 (A) 8 P 7 (C) 8 (B) 8P 7

5 0. How will the rate of following reation SO (g) + O (g) SO (g) hanges if the volume of the reation vessel is doubled (A) It will be /4 th of the initial value (B) It will be /6 th of the original value (C) It will be 8 times of its initial value (D) It will be 4 times of its initial value. At a ertain temerature, the equilibrium onstant for the reation CO(g) + H O(g) CO (g) + H (g) is 4. A mixture initially ontaining one mole of eah of arbon monoxide and steam is allowed to reah equilibrium. How many moles of arbon monoxide are now resent? (A) /4 (B) / (C) / (D) /. For A + B C + D, initial mole of A is double of B. At equilibrium moles of A and D are equal. Hene erentage dissoiation of A is (A) 50% (B) 5% (C) 75% (D) none of the above. For whih of the following equilibria, is more than? (A) A (g) + B (g) AB(g) (B) P(g) C(g) + R(g) (C) A(g) + B(g) C(g) 4. For a reation of the tye A(s) + B(g) C(g) an equilibrium mixture onsist of.0 moles of A, 0.80 moles of B, and 0.40 moles of C, in a.00 L flask. What is the value of for this reation? (A) (B) 8. 0 (C).5 (D) The vaour density of N O 4 at a ertain temerature is 0. The erentage dissoiation of N O 4 at this temerature is (A) 5. (B) 6.7 (C) 0.5 (D) values for C H 4 +H C H 6 is 50 8 atm and for C H +H C H 4 is 50 6 atm at 50C. Determine for the reation, H +C H C H 6 (A) 0 8 (B) (C) 50 8 (D) In the reation X ny, the initial vaour density of X is D and vaour density at equilibrium is d. If degree of dissoiation of X is, then is equal to D d D d (A) (B) d n n D D d (C) n d d n (D) D d

6 8. For the reation A + B C, 5 moles of A and 8 moles of B will rodue moles of C. (A) 5 (B) 4 (C) 8 (D) 9. CO (g) + H (g) CO(g) + H O(g) The for the above reation is 0.. If the reation was started with 0.45 moles of CO and 0.45 moles of H at 700, the onentration of CO when 0.4 moles of CO and 0.4 moles of H are added when the first equilibrium is attained, is (A) 0.5 M (B) 0.7 M (C) 0.4 M (D) 0.6 M 40. for the reation A( g ) B( g ) C( g ) D( g ), is 0 at 5 C. If a ontainer ontains,, 4, 5 moles er litre of A(g), B(g), C(g) and D(g) resetively at 5 C, then the reation shall (A) roeed from left to right (C) be at equilibrium [C][D] 4 5 Q 0 [A][B] 0 Q Therefore, equilibrium will shift from left to right. (B) roeed from right to left 4. The value for ertain reation is 0.5 atm at 00. Whih of the following is inorret about the reation? (A) an be alulated. (B) From this data, it is not ossible to determine about the H value of the reation. (C) (D) Neither ossible to alulate nor the relation between and. 4. In the reation A+B C+D, the initial onentration of B was.5 times that of A, but equilibrium onentration of A and B are found to be equal. The equilibrium onstant for the reation is (A) 4 (B) 6 (C) (D) 4. The of a reation is 0 atm at 00 and 4 atm at 400. The inorret statement about the reation is (A) the reation is exothermi. (B) the E of forward reation is more than that of bakward reation. a (C) the rate of bakward reation inreases more than that of forward reation with inrease of temerature. (D) the differene between heat of reation at onstant ressure and that at onstant volume is RT. dereases with temerature. Hene, H must be ve as evident from the equation. d n H dt RT H E (FR) E (BR) a E (FR) E (BR) a a a 44. The artial ressure of CH OH, CO and H in the equilibrium mixture for the reation, CO + H CH OH, at 47 o C are.0,.0 and 0. atm. resetively. The value of for the deomosition of CH OH to CO and H is (A) 0 atm (B) 0 atm

7 (C) 50 atm (D) 5 0 atm 45. At equilibrium whih relation is true? (A) The sum of free energy of rodut = sum of free energy of reatant. (B) The sum of free energy of rodut sum of free energy of reatant. (C) The sum of free energy of rodut sum of free energy of reatant. (D) Can t be deided like this. 46. The equilibrium onstant for the reation SO ( g ) O ( g ) SO ( g ) is 5. If the equilibrium onstant mixture ontains equal moles of SO and SO, the equilibrium artial ressure of O gas is (A) 0. atm (B) atm (C) 0.0 atm (D) 0.04 atm [SO ] 5 [O ][SO ] [O ] SO + O SO. Starting with moles of SO and mol of O in L flask, mixture required 0.4 moles of MnO 4 in aidi medium. Hene, is (A) (B) 0.4 (C).6 (D) Haemoglobin (Hb) forms bond with oxygen and gives oxy Haemoglobin (HbO ). This roess is artially regulated by the onentration of H O + and dissolved CO in blood as HbO + H O + + CO H + Hb CO + O + H O If there is rodution of lati aid and CO in a musular exerise then (A) more O is released (B) more HbO is formed (C) both (A) and (B) (D) CO will be formed 49. PCl 5 is 40% dissoiated when ressure is atm. It will be 80% dissoiated when ressure is aroximately (A) 0. atm (B) 0.5 atm (C) 0. atm (D) 0.6 atm 50. The reation A+B C+D, is studied in a one litre vessel at 50C. The initial onentration of A was n and that of B was n. When equilibrium was attained, equilibrium onentration of C was found to be equal to the equilibrium onentration of B. What is the onentration of D at equilibrium? (A) n/ (B) (n /) (C) (n n/) (D) n 5. The equilibrium onstant C for the reation SO (g) + NO (g) SO (g) + NO(g) is 6. If mole eah of all four gases is taken in dm vessel then the equilibrium onentration of NO would be (A) 0.04 M (C) 4.4 M (B) 0.6 M (D).6 M

8 5. When a mixture of N and H in the volume ratio of : 5 is allowed to reat at 00 and 0 atm. ressure, 0.46 mole fration of NH is formed at equilibrium. The for the reation is (A) (B) (C) (D) For the given reation A(s) + B(g) C(g) + D(s) + E(s) the degree of dissoiation of B was found to be 0% at 00 and 4% at 500, the rate of bakward reation (A) inreases with inrease in ressure and temerature (B) inreases with inrease in ressure and derease in temerature (C) deends on temerature only and dereases with inrease in temerature (D) inreases with inreasing the onentration of B and inreasing the temerature 54. In the reation A (g) + 4B (g) AB 4 (g), H 0. The deomosition of AB 4 (g) will be favoured at (A) low temerature and high ressure (B) high temerature and low ressure (C) low temerature and low ressure (D) high temerature and high ressure AB 4 (g) A (g) + 4B (g) H = ve It is an exothermi reation and hene favoured at low temerature. n for the reation is +. Therefore, low ressure will favour the forward reation 55. In 98, Fritz Haber, a German hemist, reeived the Nobel Prize in hemistry for his work on develoing a diret synthesis of ammonia on a ommerial sale. Ammonia, whih is used heavily by farmers as a fertilizer, is rodued ommerially by the Haber s roess: N (g) + H (g) NH (g) Commerially, this reation is erformed at high temerature and in the resene of a heterogeneous atalyst (iron oxide) to inrease the rate of the reation. Whih of the following "forms" of iron oxide would be the most effetive for inreasing the rate of the reation? (A) g of iron oxide ellets (0 small sherial ellets) (B) g of iron oxide ellets ( large sherial ellet) (C) g of iron oxide owder (D) g of iron oxide ket on a table outside of the reation vessel Iron oxide owder has large surfae area and hene would be most effetive for inreasing the rate of the reation. 56. For this reation at equilibrium, whih hanges will inrease the quantity of Fe(s)? Fe O 4 (s) + 4 H (g) Fe(s) + 4 H O(g) H > 0. inreasing temerature. dereasing temerature. adding Fe O 4 (s) (A) only (B) and only (C) and only (D),, and As H is ositive, inreasing the temerature will shift the reation in forward diretion. 57. The thermohemial equation reresenting the dissoiation of AB is as follows: AB (g) AB(g) + B (g) H = +40 kals Inorret statement about this reation is (A) The of the reation will derease with inrease of temerature (B) Carrying out the reation in a larger vessel (losed) will favour the equilibrium to roeed in forward diretion. (C) H and E are not equal

9 (D) Adding B (g) in the reation mixture will derease the yield of AB 58. The of a reation is 00 mol L at 7 C. Hene, the of the reation will be (A) 4.6 atm (B).8 atm (C) 4.04 atm Unit of indiates that n = 00 So, = =.8 atm RT For a hyothetial reation A(g) + B(g) C(g) + D(g) Ourring in a single ste, the seifi rate onstant of forward reation at 7 C is mol Lmin. When the reation in question is arried out at 7 C it is found that the onentration of D is twie that of A at equilibrium. The seifi rate onstant of the bakward reation is thus (A). 0 mol Lmin (B) 0.5 mol Lmin (C).0 0 mol Lmin From the given data: Equilibrium onstant () = 4 k = k, where k and k are the rate onstants of forward and bakward reations resetively. k = =.0 0 mol Lmin 60. A vessel at 000 ontains CO with a ressure of 0.5 atm. Some of the CO is onverted into CO on the addition of grahite. The value of if the total ressure at equilibrium is 0.8 atm is (A).8 atm (B) atm (B) 0. atm (D) 0.8 atm CO (g) + C(s) CO(g) At equilibrium (0.5 x) Initially = 0.5 atm CO x At equilibrium, total ressure = (0.5 + x) 0.8 = (0.5 + x) x = 0. ( CO ) ( 0.) = =.8 atm ( ) (0.5 0.) CO 6. The moleular weight of PCl 5 is 08. but when heated to 0 C, it is redued to 4. The extent of dissoiation of PCl 5 at this temerature will be (A) 6.8% (B) 68% (C) 46% (D) 64% Moleular weight before dissoiation Moleular weight after dissoiation + = 08. =.68 4 = NO is involved in the formation of smog and aid rain. A reation that is imortant in the formation of NO is O (g) + NO(g) O (g) + NO (g) = If the air over a setion of New Delhi ontained M of O, M of NO, M of NO and 8. 0 M of O, what an we onlude? (A) There will be a tendeny to form more NO and O. (B) There will be a tendeny to form more NO and O. (C) There will be a tendeny to form more NO and O.

10 (D) There will be no tendeny for hange beause the reation is at equilibrium. 4 [O ][NO ] (8. 0 )(.5 0 ) Q = 6 5 [O ][NO] (.0 0 )(.0 0 ) = = As Q, the reation will have a tendeny to move forward. 6. Consider the following gas hase reation at equilibrium Cl (g) + F (g) ClF (g) If the onentration of F (g) is suddenly doubled, whih of the following best desribes what will haen? (A) The onentration of both F (g) and Cl (g) will derease; ClF (g) will inrease (B) The onentration of ClF (g) will derease; Cl (g) and F (g) will both inrease (C) The onentration of all three seies will be unaffeted (D) It is imossible to tell without the value of the equilibrium onstant Inreasing the onentration of the reatant makes Q. So, the reation moves forward. 64. A 0 litre box ontains O and O at equilibrium at 000. = for O O. Assume that P O >> P O and if total ressure is 7. atm, then artial ressure of O will be (A) atm (B) atm (C) atm (D) atm 65. The equilibrium onstant for the reation N (g) + O (g) NO(g) is at 00. In the resene of a atalyst the equilibrium is attained 0 times faster. Therefore, the equilibrium onstant in resene of the atalyst at 00 is (A) 4 0 (B) (C) When the reation is arried out in resene of a atalyst, it will atalyse both the forward and bakward reations equally. So, the equilibrium onstant will remain same. 66. For the gas hase reation C H 4 (g) + H (g) C H 6 (g), H =.7 kal arried out in a vessel, the equilibrium onentration of C H 4 an be inreased by (A) inreasing temerature (B) dereasing ressure (C) removing some H (D) adding some C H 6 (A, B, C, D). C H 4 (g) + H (g) C H 6 (g) H =.7 kal. Conentration of C H 4 will inrease as all the fators are favouring bakward reation. High temerature, low ressure, derease in onentration of H and inrease in onentration of C H 6 will favour bakward reation. 67. for a reation at 5C is 0 atm. The ativation energy for forward and reverse reations is and 0 kj/mol resetively. The for the reation at 40C will be (A) 4. 0 M (B). 0 M (C). 0 M (D) 4. 0 M Enthaly hanged of a reation is given by H = (E a ) f (E a ) b where, (E a ) f and (E a ) b are energies of ativation for the forward and bakward reations. H = 0 = 8 kj/mol for the reation at 5C = 0 atm. Sine, is exressed in atmoshere, n = + = (RT) n 0, = = 0.4 M

11 at 40C is given by 40 H log.0r 5 T T = = ( ) 40 /( ) 5 = 0.85 ( ) 40 = = 0.4 M 68. For the deomosition reation NH COONH 4 (s) NH (g) + CO (g) The = atm. The total ressure of gases at equilibrium when mole of NH COONH 4 (s) was taken to start with would be (A) atm (B) atm (C) atm (D) atm NH COONH 4 (s) NH (g) + CO (g) = atm If the P is the total ressure at equilibrium = P P P = = P =.9575 = In an equilibrium reation for whih G = 0 the equilibrium onstant should be equal to (A) zero (B) 0 (C) (D) 70. The deomosition of ammonium arbonate at 0C is reresented as NH COONH 4 (s) NH (g) + CO (g) The equilibrium onstant is 0 6 atm. What is the total ressure of gases in equilibrium with NH COONH 4 (s) at 0C? (A) 80 6 atm (C) 60 atm (B) 0 atm (D) 90 4 atm 7. When sulhur in the form of S 8 is heated at 900, the initial ressure of one atom falls by 9% at equilibrium. The is (A).6atm (B) 0.7 (C).55atm (D) 5. S 8(g) 4S (g) Initially 0 At equilibrium = 0.7 =.6 4 [P ] 4 (.6).55 atm [P ] 0.7 S S8 atm atm 7. Two moles of an equimolar mixture of two alohols R OH and R OH are esterified with one mole of aeti aid. If 80% of the aid is onsumed and the quantities of ester formed under equilibrium are in the ratio of :, what is the value of equilibrium onstant for the esterifiation of R OH? (A) ~.7 (B) ~.9 (C) ~. (D) ~.0

12 7. LIST I LIST II (a) = 0 atm () No effet of ressure on the yield of the rodut (b) H (g) + I (g) HI(g) () H = E RT () N + H NH, H = ve () Nonsontaneous roess (d) G 0 (4) dereases with temerature P, T Codes a b d (A) 4 (B) 4 (C) 4 (D) The equilibrium onstant of the reation C H C 6 H 6 is 4.0 at temerature T. If the equilibrium onentration of C H is 0.5 moles/ litre, the onentration of C 6 H 6 is (A) 0.5 M (B).5 M (C) 50 M (D) 0.5 M 75. The equilibrium SO Cl (g) SO (g) + Cl (g) is attained at 5C in a losed vessel and He is introdued, whih of the following statement is orret (A) Conentrations of SO, Cl and SO Cl will hange (B) More Cl is formed (C) Conentration of SO is redued 76. In the system LaCl (s) + H O(g) + heat LaClO(s) + HCl(g), more water vaour is added to re establish the equilibrium. The Pressure of water vaour is doubled. The fator by whih ressure of HCl will hange is (A) (B) (C) (D) Liquid NH ionizes to a slight extent. At 60 C, its ioni rodut, [ NH ][ NH ] 0 6 NH 4 The number of NH ions resent er ml of ure liquid NH are (assuming that N A = 6 0 ) (A) 00 ions (C) 600 ions (B) 400 ions (D) 500 ions 78. The standard state Gibb s free energy hange for the isomerization reation, is entene trans entene is.67 kj mol at 400, if more trans entene is added to the reation vessel (A) more is entene is formed (B) equilibrium shifts in the forward diretion (C) equilibrium remains unaltered (D) more trans entene is rodued