UNIT : 7 EQUILIBRIUM UG Chemistry... · at equilibrium are 4.8 10 2 and 1.2 10 molL 2 1 respectively. The value of K C for the reaction is : (a) 3.3 102 mol L 1(b) 3 10 mol L 1(c)

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It is said that equilibrium is established when number of molecules moving from liquid state tovapour state and number of molecules moving from vapour state to liquid state are same and it isdynamic. Equilibrium is established in both physical and chemical types of reactions. At this point oftime the rates of forward and reverse reactions become equal. Equilibrium constant Kc is expressedas the ratio of the multiplication of concentration of products to the multiplication of concentration ofreactants; concentration of each can be expressed as power of their stoichiometric coefficient.

For reaction aA + bB cC + dD

c d

c a b[C] [D]K = [A] [B]

Equilibrium constant has constant value at constant temperature and at this stage macroscopicproperties like concentration, pressure, etc become constant. For gaseous reaction Kp is taken insteadof Kc and partital pressure of gaseous reactants and products are expressed instead of concentrations.The relation between Kp and Kc is expressed as Kp = Kc(RT)ng. In which direction reaction willoccur (forward or reverse) can be expressed by reaction quotient Qc which is equal to Kc atequilibrium. Le Chatelier's principle, mentions that if the equilibrium gets disturbed by change in factorslike concentration, temperature, pressure etc., then equilibrium will move in the direction whereby theeffect has been minimised or made negligible and the value of equilibrium constant will not change.This can be used in industries to know how equilibrium can be obtained by study of changes in factorslike concentration, pressure, temperature, inert gas etc. In industries, we can change or control factorsaccordingly so that reaction shifts from reactants to products (left to right). If catalyst is used, onlythe rate of required reaction will increase but no change will occur in amounts of reactants orproducts because the effect on forward and reverse reactions will be the same and so equilibriumconstant will not change.

The substances which allow the electric current to pass through their aqueous solutions arecalled electrolytes. Acid, base and salt are electrolytes because their aqueous solutions conduct electriccurrent. The reason for the conduction of electric current in aqueous solution of electrolyte is theformation of ions due to dissociation or ionisation which conducts electric current. While the weakelectrolytes are incompletely dissociated and so the equilibrium is established between its ions andundissociated molecules. This is called ionic equilibrium.

According to Arrhenius ionisation theory, acid is called a substance which gives hydrogen ion

(H+) and base is called a substanec which gives hydroxyl ion (OH –) on ionisation. According toBronsted - Lowry theory, acid is defined as a proton donor and base is defined as proton acceptor.Each acid has its conjugute base and each base has its conjugate acid. Hence, it is known asconjugate acid - base or proton - transfer theory. Proton is tranferred between acid and base.

UNIT : 7 EQUILIBRIUMImportant Points

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Bronsted - Lowry is more general than Arrhenius definition. According to Lewis' definition, acidmeans a substance which accepts a pair of electrons and base is a substance which donates a pairof electrons. This definition can be applied to organic chemistry, complex compounds chemistry inaddition to acid-base. Hence, it is considered universally acceptable. Ionisation constant is also anequilibrium constant. The ionisation constants of weak acid (Ka) and weak base (Kb) can be deter-mined. Concentration of acid can be expressed as pH = –log10[H3O+]. Hence, pH scale is determinedfor acid - base. Similary, concentration of OH – can be expressed as pOH = –log10[OH –], ionisationconstant of water as pKw = –log10Kw [H3O+] and [OH –] can be calculted by the use ofrelation pKw = pH + pOH. If pH < 7 solution will be acidic, pH > 7 solution will be basic and pH= 7 solution will be neutral.

Different salts can be obtained by neutralisation of strong or weak acid and strong or weakbase. In such salts, acidic, basic and neutral salts are included. When such salts react with water,hydration (hydrolysis) reaction occurs and solution obtained can be acidic, basic or neutral. This is alsoan equilibrium reaction and so corresponding equilibrium constant for it can be determined. Hydrolysisconstant is expressed as Kh. pH or pOH can be calculated from the values of Ka and Kb and thevalue of Kh characteristic for the particular salt. Some solutions are such whose pH does not changeby addition of small amount of acid or base or in case they are being diluted. Such solutions are calledbuffer solutions which can be acidic, basic or of neutral type. The control of pH is useful in thecontrol of biological reactions in our body and chemical reactions in analytical chemistry, industries etc.

Sparingly soluble salts (whose solubility is less than 0.01M in water) dissolve in water dependingon their solubility and equilibrium is established. Hence, equilibrium constant for this can beobtained which is known as solubility product constant or solubility product of the sparingly soluble salt.The study of effect of common ion, acid, etc. on the solubility of sparingly soluble salt can be carriedout by application of Le Chatelier's principle. Generally, the solubility of sparingly soluble salt de-creases due to effect of common ion. This is used in qualitative analysis. By mixing two solutions,whether precipitates will be obtained or not, can be predicted by comparing concentration product Ipwith the solubility product Ksp. If Ip > Ksp precipitation will occur and if Ip < Ksp the precipitationwill not occur and if Ip = Ksp, the precipitation will not occur but solution will remain in saturated state.



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M.C.Q.

1. Three gaseous equilibria have values of equilibrium constants as 1k , ,2k .3k resp.

(i) A + B 1K C (ii) B +C 2K P + Q (iii) A + 2B 3K P + Q

What is the relation between 1k ,k2, .3k (?)

(a) 2

13 K

KK (b) 213 KKK (c) 321 KKK (d) 1321 KKK

2. Three gaseous equilibria have value of equilibrium constants as 321 ,, KKK respectively..

(i) 2 2 1N O 2 NO (K )

(ii) 2 2 2 2N 2O 2 NO (K )

(iii) 2 2 32NO O 2NO (K )

What is the relation between 321, KandKK (?)

(a) 213 KKK (b) 321 KKK (c) 312 KKK (d) 1 2 3K K K K 3. The equilibrium constant for the reaction,

2(g) 2(g) (g)N O 2NO

temp2000kat104.4is 4In presence of a catalyst, equilibrium is attained ten times faster. Therefore the equilibrium constant,in presence of catalyst at 2000K is........(a) 4104.4 (b) 5104.4 (c) 3104.4 (d) difficult to compute

4. For the following reaction in gaseous phase

2 21CO O CO2

C PK K is

(a) 21

RT (b) 21

RT (c) RT (d) 1RT

5. For the reaction equilibrium, 2 4(g ) (g)N O 2NO the concentration of 2 4N O and 2NO

at equilibrium are 24.8 10 and 2 11.2 10 molL respectively. The value of CK for the reactionis :(a) 12 Lmol103.3 (b) 11 Lmol103 (c) 13 Lmol103 (d) 13 Lmol103

6. Which one of the following statements is not true ?(a) The conjugate base of 2

442 HPOisPOH(b) 14PP OHH for all aqueous solutions at 298 k

(c) 8isHClM101ofP 8H

(d) baselewisaisNH3



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7. What is the equilibrium expression for the reaction.

4 2 4 10(s)(s) (g)P 5O P O

(a) 524

104

OPOPKc (b) 52O

1Kc (c) 24

104

OP5OPKc (d) 52OKc

8. For the reaction

(g) 2(g) 2(g)CO Cl COCl then

p

c

KK is equal to

(a) 1

RT (b) RT (c) RT (d) 1.0

9. The equilibrium constant for the reaction

2(g) 2(g) (g)N O 2 NO

at temperature. 4104isk300 The value of Kc for the reaction1 1

2(g) 2 22 (g) (g)NO N O at thesame temperature is:(a) 2105.2 (b) 4104 (c) 0.02 (d) 50

10. Hydrogen ion concentration in Lmol in a solution of 5.4PH will be,

(a) 61098.3 (b) 61068.3 (c) 61088.3 (d) 81098.3 11. The equilibrium constants 1Kp and 2Kp for the reactions, X 2Y and Z P Q respectively..

are in the ratio of 1:9. If the degree of dissociation of x and z are equal then the ratio of total pressureat these equlibria is.(a) 1:36 (b) 1:1 (c) 1:3 (d) 1:9

12. In a reaction, O 1(g) 2(g) 3 (g)CO 2H CH OH ΔH 92 KJ mol concentration of hydrogen,

carbon monoxide and methanol become constant at equilibrium. what will happen if an inert gas isadded to the system.?(a) reaction becomes fast (b) reaction becomes slow(c) equilibrium state disturbs (d) equilibrium state remains undisturbed

13. At 473 k, equilibrium constant KC for the reaction3

5(s) 3(g) 2(g)PCl PCl Cl is 8.3 10 what is the value of KC for the reverse reaction at the same temperature ?(a) 3103.8 (b) 120.48 (c) 3106.16 (d) 31015.4

14. At 473 k, equilibrium constant KC for a reaction,

3 -1

3(g) 2(g)5 sPCl PCl Cl is 8.3 10 (ΔH 124 KJmol ) What would be the effect on KC if(i) more PCls is added



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(ii) the pressure is increased(iii) the temp is increased(a) KC remains unchanged, unchanged, increase.(b) KC increases, increases, decreases.(c) KC remains unchanged, increase, unchanged.(d) KC decreases, increases, unchanged.

15. The equilibrium constant for the reaction,4

2(g) 2(g) (g)N O 2NO is 4 10 at 2000 k temperature. what is the value of kc for the reaction

2(g) 2(g) (g)3 3N O 3 NO2 2

(a) 4104 (b) 6108 (c) 4108 (d) 41016 16. For the reversible reaction

2(g) 2(g) 3(g)N 3H 2NH at 500 c the value of

KP is 51044.1 . what would be the value of KC for the same reaction

(a) 25 500082.0/1044.1 (b) 25 773314.8/1044.1

(c) 25 773082.0/1044.1 (d) 25 773082.0/1044.1 17. The following equilibria are given

2 2 3 1N 3H 2NH K

2 2 2N O 2NO K

2 2 2 31H O H O K2

3 2 252 NH O 2 NO 3H O2 The equilibrium constant of the reaction

in terms of 1 2 3k , k and k is

(a) 1 2 3k k / k (b) 21 3 2k k / k (c) 3

2 3 1k k / k (d) 1 2 3k k k

18. The KaP of a weak acid HA is 4.80 The pKb of a weak base BOH is 4.78 The HP of an aqueoussolution of the corrosponding salt BA will be(a) 9.58 (b) 4.79 (c) 7.01 (d) 9.22

19. The equilibrium constant for the reaction2

3(g) 2(g) 2(g)1SO SO O Kc 4.9 102

The value for the KC of the reaction

2(g) 2(g) 3(g)2SO O 2SO will be

(a) 416 (b) 31040.2 (c) 2108.9 (d) 2109.4 20. HP of 0.1 M solution of weak acid is 3. The value of ionisation constant Ka of acid is

(a) 1103 (b) 3101 (c) 5101 (d) 71 1 0



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21. A vessel contains 2CO at 1000k temperature with a pressure 0.5 atm.some of 2CO is converted in

to CO on addition of graphite. If total pressure at equilibrium is 0.8 atm the value of KP is:(a) 3 atm (b) 0.3 atm (c) 0.18 atm (d) 1.8 atm

22. Three reactions involving 2 4H PO are given below..

(i) 3 4 2 3 2 4H PO H O H O H PO

(ii) - 22 4 2 4 3H PO H O HPO H O

(iii) - - 22 4 3 4H PO OH H PO O

In which of the above does -42POH act as an acid.

(a) (i) only (b) (ii) only (c) (i) and (ii) (d) (iii) only23. For the reaction

2(g) (g) 2(g)2NO 2NO O6Kc 1.8 10 at 184 c R 0.0831 KJ/mol.K

When KP and KC are compared at C184 it is found that :(a) whether Kp is greater than less than or equal to Kc depends upon the total gas pressure(b) Kp=Kc(c) Kp<Kc(d) Kp>Kc

24. Water is a(a) Protophobic solvent (b) Protophilic solvent(c) Amphiprotic solvent (d) Aprotic acid

25. Ammonium ion is(a) Conjugate acid (b) Conjugate base(c) Neither an acidnor a base (d) both an acid and a base.

26. Species acting both as bronsted acid and a base is(a)

4HSO (b) 32CONa (c) 3NH (d) -OH

27. A solution of an acid has 70.4PH find out the concentration of . wOH pK 14

(a) M105 10 (b) M104 10 (c) M102 5 (d) M109 4

28. The conjugate base of 2 4H PO is

(a) 34PO (b)

4HPO (c) 43POH (d) 24HPO

29. What is the conjugate base of OH ?

(a) 2O (b) OH2 (c) O (d) 2O30. An example for lewis acid is

(a) Ammonia (b) Aluminium chloride(c) Pyridine (d) Amines.

31. Which of the following molecule act as a lewis acid ?(a) OCH 23 (b) PCH 33 (c) NCH 33 (d) BCH 33



157

32. In a given system, water and ice are in equilibrium. If pressure is applied to the above system, then,(a) More ice is formed (b) Amount of ice and water will remain same(c) More ice is melted (d) Either (a) or (c)

33. In 2 22 HI H I H 0 the forward reaction is affected by change in(a) Catalyst (b) Pressure (c) Volume (d) Temp

34. In which case KP is less than KC (?)(a) 5(g) 3(g) 2(g)PCl PCl Cl (b) 2(g) 2(g) (g)H Cl 2HCl

(c) 2 2 3(g)2 SO O 2SO (d) all of these.

35. If 1K and 2K are respective equlibrium constants for two reaction,

6(g) 2 (g) 4(g) (g)XeF H O XeOF 2HF

4(g) 6 4(g) 3 2(g)XeF XeF XeOF XeO F the equilibrium constant for the reaction

4(g) (g) 3 2(g) 2 (g)XeF 2HF XeO F H O will be

(a) 21 KK (b) 12 KK (c) 12 K/K (d) 21 K/K36. For a homologous reaction,

3 2 24 NH 5O 4 NO 6H O the dimensions of equilibrium constant KC is(a) 10.conc (b) 1.conc (c) 1.conc (d) It is dimensionless

37. For a reversible reaction, if the concetration of the reactants are doubled, the equilibrium constantwill be(a) The same (b) Halved (c) Doubled (d) One fourth

38. The molar solubility of a sparingly soluble salt 4AB is 's' litmol The corrosponding solubility product

KSP is given in terms of KSP by the relation

(a) 1

4

SPKS 128

(b) 1

4

SPS 128 K (c) 1

5

SPS 256 K (d) 1

5

SPS K / 256

39. The solubility product of a salt having general formula MX2 in water is 12104 The concentrationof 2M ions in an aqueous solution of the salt is:

(a) M104.0 10 (b) M101.6 4 (c) M101.0 4 (d) M102.0 6

40. HP of 0.005 M calcium acetate ( 74.4COOHCHofP 3Ka ) is

(a) 7.04 (b) 9.37 (c) 9.26 (d) 8.3741. One of the following equilibria is not affected by change in volume of the flask.

(a) s(g) 3(g) 2(g)PCl PCl Cl (b) 2(g) 2(g) 3(g)N 3H 2NH

(c) 2(g) 2(g) (g)N O 2NO (d) 2 2(g) 2(g) 2(g)SO Cl SO Cl



158

42. Equal volmes of two solution of HH PThemixedare4and3P of the resulting solution will be(a) 7 (b) 3.5 (c) 2.96 (d) 3.26

43. 8H 10ofP M solution of Hcl in water is(a) 8 (b) -8 (c) between 7 and 8 (d) between 6 and 7

44. A certain buffer solution contains equal concentration of .HXandX Ka for HX is 810 . The HP of buffer is(a) 3 (b) 8 (c) 11 (d) 14

45. The solubility product of AgCl is kat 298104 10 The solubility of 2CaClM0.04inAgCl will be

(a) M102 -5 (b) M101 -4 (c) M105 -9 (d) M102.2 -446. Calculate concentration of sodium acetate which should be added to 0.1 M solution of

aK3CH COOH P 4.5 to give a solution of 5.5PH

(a) 1.0 M (b) 0.1 M (c) 0.2 M (d) 10.0 M47. Which of the following is a base according to lowry-bronsted concept ?

(a) I (b) OH3 (c) HCl (d) 4NH

48. According to lowry-bronsted concept which one of the following is considered as an acid ?(a) OH3 (b) 3BF (c) OH (d) Cl

49. The conjugate acid of 2NH is

(a) 4NH (b) 3NH (c) 42HN (d) OHNH2

50. conjugate base of hydrazoic acid is

(a) 3HN (b)

2N (c) 3N (d) 3N

51. In which of the following reaction 3NH acts as acid ?

(a) ClNHHClNH 43 (b) 43 NHHNH

(c) 3 2 21NH Na NaNH H2

(d) 3NH cannot act as acid.

52. Consider the following reactions.(i) 2

3 2 3CO H O HCO OH

(ii) 2 2 2 3CO H O H CO

(iii) 3 2 4NH H O NH OH.

(iv) 2 3HCl H O Cl H O Which of the pairs of reaction proves that water is amphoteric in character ?(a) (i) and (ii) (b) (ii) and (iii) (c) (iii) and (iv) (d) (i) and (iii)

53. One of the following is a bronsted acid but not a bronsted base :(a) SH2 (b) OH2 (c)

3HCO (d) 3NH



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54. The conjugate base in the following reaction

2 4 2 3 4H SO H O H O HSO are

(a) OH,OH 32 (b) OH,HSO 24 (c) 423 SOH,OH (d)

442 HSO,SOH55. With increase in temperature, ionic product of water

(a) Decreases (b) Increases(c) Remains same (d) May increase or decrease.

56. EDTA is a/an(a) Arrhenius acid (b) Bronsted base.(c) Lewis base (d) All of above

57. The units of lonic product of water (kw) are :(a) 11 Lmol (b) 22 Lmol (c) 12 Lmol (d) 22 Lmol

58. Whichof the following weakest ?(a) 10

6 5 2 bC H NH : K 3.8 10 (b) 5b4 106.1K:OHNH

(c) 42 5 2 bC H NH : K 5.6 10 (d) 10

9 7 bC H N : K 6.3 10 59. On adding ammonia to water,

(a) Ionic product will increase (b) Ionic product will decrease(c) 3[H O ] will increase (d) 3[H O ] will decrease

60. According to lowry and bronsted system, the chloride ion Cl in aqueous solution is a(a) Weak base (b) Strong base(c) Weak acid (d) Strong acid

61. The HP of a buffer containing equal molar concentration of a weak base and its

chlorides is 5bK for weak base 2 10 log 2 0.3010

(a) 5 (b) 9 (c) 4.7 (d) 9.362. Solution of 0.1 N OHNH4 and 0.1N ClNH4 has HP 9.25.Then

bKP is(a) 9.25 (b) 4.75 (c) 3.75 (d) 8.25

63. The solubility of product barium sulphate is 9105.1 at C18 Its solubility in water at C18 is

(a) 19 Lmol105.1 (b) 15 Lmol105.1

(c) 19 Lmol109.3 (d) 15 Lmol109.3 64. The least soluble compound (salt) of the following is

(a) ZnS 23Ksp .2 10 (b) 3OH >Cl CH COO

(c) 12CsCl Ksp 1 10 (d) 52PbCl Ksp 1.7 10

65. What is the value of HP of 0.01 M glycine solution ? For glycine 31 105.4Ka and

102 107.1Ka at 298k.

(a) 3.0 (b) 10.0 (c) 6.1 (d) 7.06



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66. Solid 23NOBa is gradually dissolved in M100.1 4 32CONa solution. At what concentration of will precipitate ?

93Ksp of BaCO 5.1 10

(a) 5101.4 M (b) M101.5 5 (c) M101.8 5 (d) 78.1 10 M

67. What is the OH in the final solution prepared by mixing of 20.0 ml of 0.05 M HCl with 30.0

ml of 0.1 M 2OHBa (?)(a) 0.4 M (b) 0.05 M (c) 0.12 M (d) 0.1 M

68. The ionisation constant of 4NH OH is 51077.1 at 298 k. Hydrolysis constant of it is

(a) 12105.6 (b) 131065.5 (c) 121065.5 (d) 101065.5

69. The dissociation consant of a substituted benzoic acid at 4100.1isC25 The HP of 0.01 Msolution of its sodium salt is(a) 0 (b) 1 (c) 7 (d) 8

70. Number of H ions present in 500 ml of lemon juice of 3PH is(a) 2210506.1 (b) 2010012.3 (c) 2210102.3 (d) 201.506 10

71. Equimolar solution of the following were prepared in water separately. Which one of the solutionswill record the highest HP (?)

(a) 2SrCl (b) 2BaCl (c) 2MgCl (d) 2CaCl

72. Solubility products constants (KSP) of the salt types 2 3MX, MX and M X at temp T. are8 14 154 10 ,3.2 10 and 2.7 10 respectively. Solubility of the salts at temp. T are in the order,,

(a) 23 MXXMMX (b) MXXMMX 32

(c) MXMXXM 23 (d) XMMXMX 32

73. When H ion concentration of a solution increases(a) PH increses (b) PH decreases (c) no change in PH (d) POH decreases

74. At C25 temp. the value of bpk for 3NH in aqueous solution is 4.7. what is the value of HP of 0.1

M aqueous solution of ClNH4 with 0.1 M 3NH (?)`(a) 8.3 (b) 9 (c) 9.5 (d) 10

75. The aqueous solution of 6 5 3HCOO Na, C H NH Cl, and KCN are respectively(a) Acidic, acidic, basic (b) Acidic, basic, neutral(c) Basic, acidic, basic (d) Basic, neutral, basic

76. KSP of 3AgIO is -8101 at a given temperature what is the mass of 3AgIO in 100 ml of itssaturated solution ?(a) gm4100.1 (b) gm2103.28 (c) 32.83 10 gm (d) gm7100.1



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77. PH of a solution containing 50 mg of sodium hydroxide in 10 dm3 of the solution is(a) 9 (b) 3.9031 (c) 10.0969 (d) 10

78. Which one of the following has the lowest HP value ?(a) HClM1.0 (b) KOHM1.0 (c) HClM01.0 (d) KOHM01.0

79. Equal volumes of three basic solutions of 11,12 and13 are mixed in a vessel. what will be the H+

ion concentration in the miture ?(a) 111.11 10 M (b) M107.3 12 (c) M107.3 11 (d) 121011.1 M

80. Columm I Column II(Buffer Solution) PH

(A) O.1M CH3 COOH + 0.01M (p) 3.8 CH3 COONa

(B) 0.0 1M CH3COOH+0.1M CH3COONa (q) 5.8(C) 0.1M CH3COOH+0.1M CH3COONa (v) 7.0(D) 0.1M CH3COONH4 (s) 4.8(Pka Of CH3COOH=Pkb of NH4OH=4.8)(a) A-r, B-q, C-s, D-p(b)A-q, B-p, C-s, D-r(c)A-q, B-p, C-r, D-s(d)A-r, B-q, C-s, D-p

81. PH of a soda water bottle is(a) > 7 (b) = 7(c) < 7 (d) unpredictable.

82. Statement :1 PH of 10-8 HCl solution is not equal to 8Statement :2 HCI does not dissociate properly in very dilute solution.(a) Statement -1 is true. Statement -2 is true. Statement-2 is a correct explanation for statement-1(b) Statement- 1 is true. Statement-2 is true. Statement-2 is not a correct explanation of statement-1(c) Statement-1 is true. Statement-2 is false.(d)Statement-1 is false.

Statement-2 is true.83. For preparing a buffer solution of PH 6 by mixing sodium acetate and acetic acid , the ratio of

concentration of salt and acid should be, (Ka=10-5)(a) 1:10 (b) 10:1(c) 100:1 (d) 1:100

84. The KSP of CuS, Ag2S and HgS are 10-32, 45104 and 10-54 respectively. The solubility ofthese sulphides are in order of(a) 2Ag S HgS CuS (b) 2Ag S CuS HgS

(c) 2HgS AgS CuS (d) CuS > Ag2S > HgS



162

85. The PH of neutral water is 6.8 .Then the temperature of OH2

(a) is 250C (b) is more than 250C(c) is less than 250C (d) can not be predicted.

86. On adding 0.1 M solution each of 2 2Ag ,Ba and Ca ions. in a 42SONa solution. species firstprecipitated is

11 6 5SP 4 SP 4 SP 2 4K of BaSO 10 , K of CaSO 10 ,K of Ag SO 10

(a) 4BaSO (b) 4CaSO (c) 2 4Ag SO (d) all of these

87. The solubility of 32BA is x mol L-1. It solubility product is

(a) 5x6 (b) 5x64 (c) 5x36 (d) 5x108

88. How much volume of 0.1 M 3CH COOH should be added to 50ml of 0.2 M 3CH COONa If wewant to prepare a buffer Solution of HP 4.91. given pKa for acetic acid is 4.76(a) 80.92 ml (b) 100 ml (c) 70.92 ml (d) 60.92 ml

89. The ionzation constant of formic acid is 4108.7 . Calculate ratio of sodium formate & formic acidin a buffer of HP 4.25(a) 9.63 (b) 3.24 (c) 6.48 (d) 3.97

90. The ionization constants of HF is 4108.6 . Calculate ionization constant of corresponding conjugatebase.(a) 10109.1 (b) 10107.1 (c) 11105.1 (d) 11109.2

91. The ionization constant of formic acid is 4108.1 around what HP will its mixture with sodiumformate give buffer solution of highest capacity(a) 3.74 (b) 7.48 (c) 4.37 (d) 3.96

92. What is PH of our blood ? why does it remains constant inspite the variety of the foods and spiceswe eat ?(a) of blood is 5.4. It remains constant because.it is acidic.(b) of blood is 7.4. It remains constant because.it is buffer.(c) of blood is 10.8.It remains constant because.it is basic.(d) of blood is 7.0. It remains constant because it is neutial.

93. The precipitate of 102 SPCaF (K 1.7 10 ) is obtained when equal volumes of the following are

mixed.(a) FM10CaM10 424 (b) FM10CaM10 322

(c) FM10CaM10 325 (d) FM10CaM10 523

94. A certain buffer solution contains equal concentrations of X and HX The Ka for HX is 810 TheHP of buffer is

(a) 8 (b) 3 (c) 7 (d) 4



163

95. The correct order of increasing OH3 in the following aqueous solution is.

(a) 2 2 4 20.1 M H S 0.1 M H SO 0.1 M NaCl 0.1 M NaNO

(b) 2 4 2 20.1 M H SO 0.1 M NaCl 0.1 M NaNO 0.1 M H S

(c) 2 2 2 40.1 M NaNO 0.1 M NaCl 0.1 M H S 0.1 M H SO

(d) 2 2 2 40.1 M NaNO 0.1 M H S 0.1 M H SO 0.1 M NaCl 96. What is the % hydrolysis of NaCN in N/80 solution when dissociation constant for HCN is

9 14W1.3 10 & K 1 10

(a) 2.48 (b) 8.2 (c) 5.26 (d) 9.697. The KSP of 10100.4isAgCl at 298 k.solubility of AgCl is 0.04 M 2CaCl will be

(a) M102 5 (b) M101 4 (c) M105 9 (d) M102.2 498. How much sodium acetate should be added to 0.1 M solution of 3CH COOH to give a solution of

HP 5.5 3pKa of CH CooH 4.5

(a) 0.1 M (b) 1.0 M (c) 0.2 M (d) 10.0 M99. The HP of solution obtained by mixing 50ml 0.4 N HCl & 50ml 0.2 N NaOH is

(a) 2log (b) 1.0 (c) 2.0log (d) 2.0

100. Ionisation constant of 3CH COOH is 5107.1 and concentration of H ions is 4104.3 The initial

concentration of 3CH COOH molecules is

(a) 4104.3 (b) 3104.3 (c) 3108.6 (d) 3107.1 101. In the reversible reaction A B C D , the concentration of each C and D at equilibrium was

0.8 mollitre, then the equilibrium constant KC will be.(a) 6.4 (b) 0.64 (c) 0.16 (d) 16.0

102. 4 moles of A are mixed with 4 moles of B.At equilibrium for the reaction A B C D 2 molesof C and D are formed . The equilibrium constant for reaction will be

(a) 41

(b) 4 (c) 21

(d) 1

103. A reversible chemical reaction having two reactants in equilibrium. If the concentration of thereactants are doubled, then equilibrium constantwill(a) become double (b) become half(c) become 4 times (d) remains same

104. Two moles of PCls are heated in a closed vessel of 2L capacity. At equilibrium, 40 % of PCl5 isdissociated in to PCl3 & Cl2. The value of equilibrium constant is,(a) 0.266 (b) 0.53 (c) 2.66 (d) 5.3

105. The dissociation constant for acetic acid and HCN at 25 C are 5 101.5 10 and4.5 10 respectively..the equilibrium constant for reaction 3 3CN CH COOH HCN CH COO (a) 5103 (b) 5103 (c) 4103 (d) 4103



164

106. A B C D if finally the concentration of A and B are both equal but at equilibrium concentrationof will be twice of that of A. Then what will be equilibrium constant of the reaction.

(a) 94 (b) 4

9 (c) 19 (d) 4

107. If in the reacton 2 4 2N O 2NO , is that part of 42ON will dissociate, then the number of molesat equilibrium will be,(a) 3 (b) 1 (c) 1 (d) 1

108. 4.5 moles each of hydrogen and iodine heated in a sealed ten litre vessel. At equilibrium, 3 moles ofHI were found. The equilibrium constant for 2(g) 2(g)H I 2HI(g) is(a) 1 (b) 5 (c) 10 (d) 0.33

109. The rate constant for forward and backward reaction of hydrolysis of ester are 2 31.1 10 &1.5 10 per minute respectively. Equilibrium constant for reaction is,

3 2 5 2 3 2 5CH COOC H H O CH COOH C H OH (a) 4.33 (b) 5.33 (c) 6.33 (d) 7.33

110. Two moles of 3NH ,when put in to a previously evacuated vessel(1 Litre), partially dissociate in to

. 2 2N and H If at equlibrium one mole of 3NH is present, the equilibrium constant is,

(a) 22 Litremol43 (b) 22 Litremole64

27

(c) 22 Litremole3227 (d) 2 227 mol Litre16

111. What is equilibrium expression for the reaction

4 2 4 10P 5O P O

(a) 5C 2K O (b) C 4 10 2K P O / 5 A O

(c) 5C 4 10 4 2K P O / P O (d) 5C 2K 1/ O

112. Partial pressure of 2O in

2 (g) 2(g)2 Ag O 4 Ag(s) O is

(a) kp (b) kp (c) kp3 (d) 2 kp

113. For reaction 2(g) 2(g) (g) 2H CO CO H O(g) ,If the initial concentration of 22 COH and xmoles / litre of hydrogen is consumed at equilibrium, the correct expression of KP is

(a) 22

x1x (b)

2

2

x1x1

(c) 22

x2x (d) 2

2

x1x

114. Consider the imaginary equlibrium4A 5B 4x 6y

The equilibrium constant CK has unit

(a) 22 Litremole (b) 1moleLitre (c) 1litremole (d) 22 moleLitre



165

115. For reaction (g) 2(g) 2(g)1 KpCO O CO2 Kc

is equivalent to

(a) 1 (b) RT (c) RT1 (d) 2

1RT

116. For the reaction1

4(g) 2(g) 2(g) 2 (L)CH 2O CO 2H O H 170.8KJ mol Which of following statement is not true(a) Adding of )g(2)g(4 OonCH at equilibrium will cause a shift to the right(b) Thee reaction is exothermic(c) At equilibrium, concentrations of 2(g) 2 (L)CO and H O are not equal.

(d) Equilibrium constant for the reaction is given by

2

P4 2

COK

CH O

117. The reaction Quetient (Q) for the reaction

2(g) 2(g) 3N 3H 2NH

is given by

23

32 2

NHQ

N H The reaction will proceed from right to left is:

(a) Q 0 (b) CQ K (c) Q < KC (d) CQ K118. If concentration of reactants is increased by 'x' then k become

(a) )x/kln( (b) k/x (c) k+x (d) k119. Which of following is not favourable for formating SO3 formation

2(g) 2(g) 3(g)2SO O 2SO H 45.0 Kcal. (a) High pressure (b) Decreasing SO3 concentration(c) High temperature (d) Increasing reactants concentration

120. The most important buffer in blood consists of(a) HCl andCl (b) 2 3H CO and Cl (c) 2 3 3H CO and HCO (d) 3HCl and HCO

121. Given that dissociation constant for OH2 is 14WK 1 10 2 2moles / Litre What is HP of 0.001 M

NaOH(a) 10-11 (b) 310 (c) 11 (d) 3

122. Select the pKa value of strongest acid from following(a) 1.0 (b) 3.0 (c) 2.0 (d) 4.5

123. The degre of hydrolysis equilibrium

2A H O HA OH

at salt concentration of 0.001 M is 5101Ka

(a) 3101 (b) 4101 (c) 41075.6 (d) 21038.5



166

124. If bpK for fluoride ion at 250C is 10.83, the ionisation constant of hydrofluoric acid in water at thistemperature is(a) 31074.1 (b) 31052.3 (c) 41075.6 (d) 21038.5

125. Henderson's equation is AcidSaltlogpkaPH If acid gets half neutralised the value of HP will

be [pka=4.30](a) 4.3 (b) 2.15 (c) 8.60 (d) 7

126. The HP of a 0.01 M solution of acetic acid having degree of dissociation 1.25% is(a) 5.623 (b) 2.903 (c) 3.723 (d) 4.503

127. By adding 20 ml 0.1 N HCl to 20 ml 0.1 N KOH the HP of obtained solution will be :(a) 0 (b) 7 (c) 2 (d) 9

128. If the Kb value in the hydrolysis reaction6

2B H O BOH H is 1.0 10 then hydrolysis constant of salt would be

(a) 61.0 10 (b) 71.0 10 (c) 81.0 10 (d) 91.0 10129. For a sparingly soluble salt ApBq relation ship of its solubility product(KSP) with its solubility(s) is.

(a) p q p qSPK S P q (b) p q q p

SPK S P q (c) pq p qSPK S P q (d) p qpq

SPK S pq

130. How many grams )128mw(OCaC 42 on dissolving in disttile water will give saturated

solution 9 2 2SP 2 4K CaC O 2.5 10 mol l

(a) 0.0064gm (b) 0.1280gm (c) 0.0128gm (d) 1.2800gm131. If the concentration of CrO4

2– ion in a saturated solution of silver chromate is 42 10 solubilityproduct of silve chromate will be(a) 8104 (b) 12108 (c) 121012 (d) 121032

132. According to bronsted- lowry concept. correct order of relative strength of bases follows the order

(a) 3Cl CH COO OH (b) _

3Cl OH CH COO

(c) _

3OH CH COO Cl (d) 3OH >Cl CH COO

133. OHSOOHHSO 2244 Which is correct about conjugate acid base pair ?

(a) 24 4HSO is Conjugate acid of base SO

(b) 24 4HSO is Conjugate base of acid SO

(c) 24 4SO is Conjugate base of acid HSO

(d) None of these134. Which of following base is weakest

(a) 64 bNH OH:K 1.6 10 (b) 10

b256 103.8K:NHHC

(c) 4b252 105.6K:NHHC (d) 10

b72 106.3K:NHC



167

135. HClO is a weak acid. concentration of +H ion in 0.1 M solution of HClO -8Ka 5 10 will be

(a) M107.07 5 (b) M105 9 (c) M105 7 (d) M107 4

136. Upto what HP must a solution containing a precipitate of 3Cr OH be adjusted so that all

precipitate dissolves(a) upto 4.4 (b) upto 4.1 (c) upto 4.2 (d) upto 4.0

137. ClNH4 is acidic because

(a) On hydrolysis ClNH4 give weak base OHNH4 and strong acid HCl

(b) Nitrogen donates a pair of -e(c) It is a salt of weak acid and strong base(d) On hyrdolysis 4NH Cl gives strong base and weak acid

138. 100 ml of 0.04 N HCl aqueous solution is mixed with 100 ml of 0.02 N NaOH solution. The HP ofresulting solution is(a) 1.0 (b) 1.7 (c) 2.0 (d) 2.3

1 B 26 A 51 C 76 C 101 D 126 B2 C 27 A 52 C 77 C 102 D 127 B3 A 28 D 53 A 78 A 103 D 128 C4 A 29 D 54 B 79 B 104 A 129 A5 C 30 B 55 B 80 B 105 D 130 A6 C 31 D 56 D 81 C 106 D 131 D7 B 32 C 57 D 82 C 107 B 132 C8 A 33 D 58 A 83 B 108 A 133 C9 D 34 C 59 D 84 B 109 D 134 B

10 A 35 C 60 A 85 B 110 B 135 A11 A 36 B 61 D 86 A 111 D 136 D12 D 37 A 62 B 87 D 112 A 137 A13 B 38 D 63 D 88 C 113 A 138 C14 A 39 C 64 B 89 B 114 C15 B 40 D 65 D 90 C 115 C16 D 41 C 66 B 91 A 116 D17 C 42 D 67 D 92 B 117 D18 C 43 D 68 D 93 B 118 D19 A 44 B 69 D 94 A 119 C20 C 45 C 70 B 95 C 120 C21 B 46 A 71 B 96 A 121 C22 B 47 A 72 A 97 C 122 A23 D 48 A 73 B 98 B 123 A24 C 49 B 74 A 99 B 124 C25 A 50 C 75 C 100 C 125 A

ANSWER KEY



168

Hint : Chemical equilibrium .Hint :1. Addition of (1) and (2) gives (3) then

1 2

C P QK K

A B B C

32 K

BAQP

213 KKK when the addition of equilibria leads to another equilibria then the product of their equilibria constants

gives the equilibria constant of the resultant equilibrium.3. The value of equilibrium constant does not change in presence of catalyst.4. Formula :

(g)Δn

(g) p r

Kp Kc(RT)Δn n - n

6. OH2 is also present in HClM101 -8 solution. So due to self ionisaion of OH2 ,

2H O H OH

K298atM101 7

so conc. of H ion in solution increase due to self ionisation of OH2 Hence HClofPH solutiondecreases and its value is less than 7.

9. 2(g) 2(g) (g)N O 2 NO

2 2

2NO

pN O

PKP P

For reaction,

2 (g) 211N O (g) O N2 2

NO

NOP P

PPK'

21

2

21

2

= 501041

Kp1

21

21 4

10.

H

H

6

P 5.4

P log H

5.4 log H

6.6 3.981 10 H



169

11 For a reaction X 2Y initialmol 1 0

at equilibrium mol 1-x 2xTotal moles = 1-x+2x = 1+x

x1x1p4x

px1x1

Px1

2x

PPKp 1

2

1

2

1

x

2Y

1

------(1)

For a reaction Z P QInitial 1 0 0

at eqm. 1-x x xTotal moles = 1+x

2

2

22

222 P

x1x1x

Px1x1x1

pxPxKp

-------(2)

36:1P:P361

PP

91

PP4

91

KpKp

212

1

2

1

2

1

18. For salt of weak acid and weak base

Hb

b

1P log Ka log kw log K21 1 1pKa pkw pk2 2 2

1 1 14.8 14 4.782 2 27.01

19. Equilibrium constant for the reaction

2(g) 2(g) 3(g)1SO O SO2

2109.41

CK

and for reaction 2(g) 2(g) 3(g)2SO O 2SO

2

C 2

1K 416.494.9 10



170

20. 33

H 101OΗ3P

5232

3 1010.1101

COHKa

21. 2(g) (g) (g)CO C 2CO initial pressure 0.5 atm 0

final pressure(0.5-x) 2xTotal pressure = 0.5 -x+2x=0.5 +x = 0.8 atm

x=0.3 atm.

2 2CO

PCO2

p (0.6)K 1.8 atm.P 0.2

22. According to lowry-bronsted acid base theory in (ii) reaction 42POH donates H ion to OH2 so

it acts as an acid.23. 1)(Kc(RT)Kp n(g) gn

4570831.0 Kc It means Kp > Kc24. Water is an amphiprotic solvent as it can accept protons as well as give protons.25. Ammonium ion 4NH is a conjugate acid of 3NH

3 2 4NH H O NH OH Bronsted base Conjugate acid

26. 4HSO can act as a bronsted acid as well as bronsted base.

24 2 4 3HSO H O SO H O

Acid

4 2 2 4HSO H O H SO OH Base

27. H 5 143 w WP 4.7 H O 1.995 10 pK 14 K 1 10

3 W 3log H O NowK H O OH

M105101.995

101OH 105

14

28. conjugate base of 42POH is 2

4HPO2

2 4 2 4 3H PO H O HPO H O Acid

29. conjugate base of OH

22 3OH H O O H O



171

30. Lewis acid always accepts a pair of e here 3AlCl accepts a pair of e.

31. BCH 33 accept a pair of e so lewis acid32. Pressure on equilibrium system increses ,so volume decreses. volume of ice is more than liquid

OH2 so more ice is malted

33. For endothermic O H reaction, change in temperature affects the equilibrium system and forwardreaction takes place . by increasing temp .

34.

64

2342

26

24

1 XeFXeFFXeOXeOFK

OHXeFHFXeOFK

and 24

223

HFXeFOHFXeOK is obtained by

1

2K

K

1

2K

KK

36.

5)(4645

24

3

62

4

(conc.)ONH

OHNOKc

1conc37. According to Le -chatelliers principle, if conc. of reactant become doubled, then forward reaction

takes place and concentration of product also increases. so equilibrium constant also remains same.

38. 44(s) (aq) (aq)AB A 4B

_ 44

SPK A B

4 5S (45) 256S 15

SPKS256

39.22 3

SPK M X 4S

11 12 332 4SP 4 10KM S 1 104 4

40. 23 32

CH COO Ca Ca 2CH COO

0.005 0.01M.0.0052

HW a C

1P log K logK log2



172

W a C1 1 1log K log K log2 22

2-101log21pka2

1pkw21

2)(214.742

11421

= 37.8137.27 41. change in volume affects number of moks per unit voulme. In a reaction

2(g) 2(g) (g)N O 2 NO no. of moles of reactants and product are equal so volume change does not affects the equilibrium.

42. H 3P 3 means H 10 M H 4P 4 means H 10 M

After mixing equal volume total 2

110101H4-3

2

101100.1 4-4

= 43

105.52101.1

4H 5.5 10 M H 4P log H log(5.5 10 ) 4 0.7404 3.26

43. HP of HCl should be less than 7. due to self ionisation of OH2

from acid 8 72H 10 M from H O H 10 M

Total 8 -7 8 8H 10 10 10 (1 10) 11 10 M H 8P log H log(11 10 ) (1.0414 8)

= 6.966.96PH

44. HP of buffer solution

a

a8

saltpK log

Acidlog K log1

log10 0 8



173

45. if x is the solubility of AgCl in 0.04 2M cacl ,

then 1Ag x mol L

M0.08x0.08x0.042lC

KSP of AgCl Ag Cl

10 94 10 Ag 5 10 M0.08

46.

3H

3

CH COONaP pka log

CH COOH

3CH COONa5.5 4.5 log

0.1

1CooNaCHlog4.55.5 3

0CooNaCHlog 3

M1CooNaCH3

47. I can accept protons and hence is a base.

50. 3 3 3N H N H Hydrazoic acid N H

53. SH2 can donate proton but can't accept proton.55. With increase in temperature, ionic product increases. because self ionisation of is endothermic

process56. EDTA is Arrhenius acid as it can give H ions in aqueous solution, bronsted base. as it can accept

protons and lewis base because N and O in it can donate lone paris of electrons.

57. WK H OH

2211 LmolLmolLmol 58. Smaller the Kb value, weaker is the base.59. On adding 3NH to water, -OH will increse,

3Kw H O OH is constant.

Therefore 3H O will decrease

61.

OH K SaltP P b log

Base [Salt] = [Base]

= 1log)102log( 5

= 4.699005.0000.3010

9.30104.699014p14P OHH



174

62.

OH OH Hb

SaltP pK log P 14 P 4.75

Base

1logp4.75 kb

01log4.75pk b

63. 2 24 (aq) 4(aq)(s)BaSO Ba So

x mol/lit x mol/lit2 2

SP 4K Ba So 2

SPK x1 19 5 12 2x (ksp) (1.5 10 ) 3.9 10 molL

64 Hint : As value of KSPis less , solubility is also less.

65. glycine (NH2CH2COOH) is more acidic than basic.overall ionisation constant

3 10a1 a 2K K K 4.5 10 1.7 10

131065.7

0.01107.65CKH 13

M100.87 7

7.0605)10log(8.7P 8H

66. KSP of 2 23 3BaCo Ba CO

M105.1101105.1Ba 5

4

92

67. O2HBaCl2HClBa(OH) 222

2Ba(OH) mole 1 neutralize HCl mol2

2Ba(OH) mole 0.5 neutralize HCl mol1 2OHBaBa(OH) 2

2

1 221.3Ba(OH) of moles no.of 2

2.50.53leftBa(OH) 2

M0.05502.5 Ba(OH) 2

or M0.1M0.052OH



175

68.14

10Wh 5

b

K 1.0 10K 5.65 10K 1.7 10

69. H K K1P P W P a logC2

2log102142

11421

= 7 + 2 - 1 = 870. M10Hmeans3P 3H

1000 ml juice contains 310 mole H ions

ml1000in106.02210ionsHno.of 233

1000500106.02210ionsHcontains juice ml 500

233

= 2010011.3 71. All alkaline earth metal chlorides 2MCl on hydrolysis will produce acidic solution

2 2 2MCl H O M(OH) 2HCl

because 2M(OH) is a weak base and HCl is a strong acid. but as we go down the group, basic

character of hydroxides increses. Hence acidic character decreses. So 2BaCl will have the highest HP .

72. (s)MX M X 1 12 8 42 2

SP SPK S S (K ) (4 10 ) 2 10 M.

13

2 3 5SP2(s) SP

KMX M 2X K 4S S 2 10 M.4

33 (s)M X 3M X

KSP =

11 15 444 4SPK 2.7 1027S S 1 10 M

27 27

4 4 52 10 1 10 2 10

.MXXMMX 23

74.

baseweakSaltlogpkP b

OH

7.501.01.0log7.4

8.35.714PH



176

75. HCOONa is a Salt of weak acid (HCOOH) and Strong base (NaOH) So it is basic. ClNHHC 356

is a Salt of weak base 256 NHHC and strong acid (HCl) so it is acidic. KCN is a Salt of Strongbase (KOH) and weak acid (HCN) so it is basic.

76.(aq)3(s) (aq) 3AgIO Ag IO

2SPK S

1 18 42 2SP

molS (K ) (1.0 10 ) 1 10 lit

litgm10283283101S 44-

34 AgIOofgm10283containsml1000

34 AgIOofgm1028.3containsml100

77. Molar concentration of 31

3

10dmmolgm40gm1050NaOH

-41.25 10 M

O H 4P l o g ( 1 . 2 5 1 0 )

9031.30.40969.0

10.09693.903114PH

78. 1 H0.1 M HCl means H 10 P 1 1 OH H0.1M KOH means OH 10 P 1 P 13

2 H0.01M HCl means H 10 P 2 2 OH H0.01M KOH means OH 10 P 2 P 12

79. H ion concentrations are 131211 10and10,10 on mixing equal volumes, H in final solution

=3

101.010110103

101010 121212131211

M.103.731011.1 12

12

80. (A) 5.814.8

0.010.1log4.8

acidSaltlogpkaPH

(B) 3.814.810 log4.80.10.01log4.8P 1-H

(C) 4.804.80.10.1log4.8PH

(D) 4.8)(4.8217pkb)(pka

21 7 PH =7.0



177

81. Soda water contains weak acid 32COH So its 7PH

83.

H K SaltP p a log

acid

acidSaltlog56

.10acidSalt1

acidSaltlog or

84.11 32 162 2Solubility of Cus (ksp) (1 10 ) 1 10 M

11 -453 315

2ksp 4 10Solubility of Ag S 1 10 M4 4

11 -54 272 5Solubility of HgS ksp 4 10 1 10 M

85. At C25 temp HP of M10H7OH 72

M10thanmoreisH7Pmeans6.8P 7HH

Self ionisation of OH2 is endothermic so by increasing temp H ion increases.

86. ksp for 2 24 4BaSo Ba SO 11 2

410 0.1 SO 2 104SO 10 M

2 24 4ksp for CaSO Ca SO

2

456

SOM100.110

ksp for 2 22 4 4Ag So Ag SO

2

43

25

SOM10(0.1)10

As value)(leastBaSOinM10SO 4102

4

it can be precipitated first

87. 3 22 3(s)A B 2A 3B

2x 3x

3223 BAksp32 )3()2( xx

32 274 xx 5108x



178

88.

H K SaltP P a log

Acid

AcidSaltlog76.44.91

1.41.15antilogof0AcidSalt0.15

AcidSaltlog

ml70.92V1.41V

10000.1

5010000.2

89. 3.74)10log(1.8pka 4

0.513.744.25pkaPAcidSaltlog H

Saltantilog of0.51 3.24

Acid

90. 114

14

b 101.47106.810

kckwK

91. Buffer Solution of highest capacity is formed at which3.74)10log(1.8pkaP 4H

93. Ionic Product of 2CaF

in (i) ksp10FCaIP 1222

(ii) obtain ppt. ksp101010IP 8232

(iii) ksp101010IP 11235

(iv) ksp101010IP 13253

94. AcidSaltAcidSaltlogpkaPH

= 8 + log 1 = 895. acidStrongSOHacidweakSH 422

2NaCl neutral NaNO basic

3Hence H O will be in the order of

4222 SOHSHNaClNaNO



179

96. NaCN is Salt of weak acid (HCN) and Strong base (NaOH) Hence

2

9

14

a

102.48

801)10(1.3

10Ck

kwh

2Percen tan ge Hydrolysis (2.48 10 )100 = 2.48

97. If x is Solubility of AgCl in 0.04 M 2CaCl , then1Ag x m ol L

Cl (0.04 2) x 0.08M

101040.08(x)

Mx 9100.5

98.

3H

3

log CH COONaP pka

1 CH COOH

3CH COONa5.5 4.5 log

0.7

34.5 + log CH COONa 1

3log CH COONa 0

3CH COONa 7 M

99. eq.g0.025010000.4HClNof0.4ml50

eq.g0.015010000.2NaOHN0.2ofml50

0.01 g eq of NaOH will Neutalilise 0.01 g eq of HCl HCl left unneutralised = 0.01 g eq

vol of Sol. =50+50 =100ml

0.1N10001000.01HCl

or H 0.1M

log(0.1)pH = 1.0

100. 3 3CH COOH CH COO H

at eq 444 104.3104.3)104.3( a

4 45

4

3.4 10 3 .4 101 .7 10 (G iven)

a 3.4 10

3106.8a



180

101.

A B C Dinitial 1 1 0 0conc.Ateqm(1 0.8) 0.8 0.8conc.(1 0.8)

0.2 0.2

0.16

2.02.08.08.0

BADCKc

102.

A B C Dinitial 4 4 0 0conc.Ateqm(4 2) 2 2conc.(4 2)

2 2

1

2222

BADCKc

103. KC remains same beacause KC is a characteristic constant.104. 5 3 2PCl PCl Cl

2 0 0

100402

100402

100602

20.8

20.8

21.2

litmolconc.

0.80.81.2moles

0.266

0.60.40.4

PClClPClKc5

23

105. Dissociation of 3CH COOH3

3 3 a1CH COOH H CH COO k 1.5 10

Dissociation of HCN: HCN 3a2H CN k 4.5 10

for a reaction

3 3CN CH COOH CH COO HCN is

410

3

2

1 103.33104.5101.5

KaKaKa



181

106. A B C D x x 0 0

2x 2x 4

xx2x2x

BADCkc

107. 2 4 2N O 2 NO 1 0(1- ) 2 Total moles = 1- +2 =1+

108. 2 2H I 2 HI from equation 2x=3

Initial 4.5 4.5 0 5.123 x

conc.at eqm. (4.5-x)(4.5-x) 2x

31.54.5H2

31.54.5I2 1

3333

IHHIKc

22

2

109. 3b

2f 101.5K101.1K

7.33101.5101.1

kkfkc 3

2

b

110. 3 2 22 NH N 3Hinitial 2 0 0conc.

At eqm.

conc. 1 21 2

3

33

2 2C 2

3

31N H 2 2 27K 64NH (1)

111. 4(S) 2(g) 4 10(s)P 5O P O

4 10C 5

4(s) 2(g)

P OK

P O

we know that concentration of a solid component is always taken as a unity

52O1Kc



182

112.(g )2 (s) (s) 22Ag O 4 Ag O

for this reaction 2Kp Po

113. 2(g) 2(g) (g) 2 (g)H CO CO H O initialconc. 1 1 0 0

At eqm. (1-x) (1-x) x x

2

2 O 2

2C O H

2H C

P P O xKpP P (1 x )

129. q p(s) (aq) (aq)ApBq PA q B

Solubility is PS qS mol/litP q

SPK (PS) (qs) qP)qp( qPS

135. 8105KaM1.0Co

CoKaH

21102

18 )1050()1.0105(

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UNIT : 7 EQUILIBRIUM UG Chemistry... · at equilibrium are 4.8 10 2 and 1.2 10 molL 2 1 respectively. The value of K C for the reaction is : (a) 3.3 102 mol L 1(b) 3 10 mol L 1(c)