1) The active mass of 64 g of HI in a 2 litre flask would be
2) The factor that changes the equilibrium constant of the reaction A2(g) + B2(g) 2AB is
a) Total pressure
d) The presence of a catalyst
3) The reaction that proceeds in the forward direction is
4) The reaction in which the yield of the products can not be increased by the application of high pressure is
5) Which one of the following information can be obtained on the basis of Le Chateliers principle?
a) Shift in equilibrium position on changing certain parameters
b) Dissociation constant of a weak acid
c) Energy change in a reaction
d) Equilibrium constant of a chemical reaction
6) Which of the following will shift the reaction PCl3 + Cl2 PCl5 to the left side?
b) Increase in pressure
c) Decrease in temperature
7) In a chemical reaction, equilibrium is said to be established when the
a) Concentration of reactants and products are equal
b) Opposing reactions cease
c) Velocities of the opposing reactions become equal
d) Temperatures of opposing reactions are equal
8) 2SO2+ O2 2SO3 + 47 kcals. If a large excess of oxygen is added to the above system in equilibrium this will
a) Shift the equilibrium to the right
b) Shift the equilibrium to the left
c) Cause no change in the equilibrium
d) Produce only an enormous amount of heat
9) In what manner will an increase in pressure affect the reaction ? C(s) + H2O(g) CO(g) + H2 (g).
a) Shift in the forward direction
b) Shift in the reverse direction
d) No effect
10) A and B are gaseous substances which react reversibly to give two moles of a gaseous product C, accompanied by the liberation of heat. When the reaction reaches equilibrium it was found that Kp = Kc. The equilibrium can not be disturbed by
a) Adding A
b) Adding C
c) Increasing the temperature
d) Increasing the pressure
11) In a chemical equilibrium, the equilibrium constant is found to be 2.5. If the rate constant of backward reaction is 3.2 x 10-2, the rate constant of the forward reaction is
12) @ On increasing the pressure three fold, the rate of reaction of
2H2S + O2® Products would increase
a) 27 times
b) 9 times
c) 3 times
d) 12 times
13) Kc for A+ B 3C is 20 at 25Â°C. If a 2 litre vessel contains 1, 2 and 4 moles of A, B and C respectively, the reaction at 25Â°C shall
a) Proceed from left to right
b) Proceed from right to left
c) Be at equilibrium
d) Not occur
14) Which of the following is least soluble?
15) Which of the following is most soluble in water?
16) Which metal sulphide has the maximum solubility in water?
17) The hydroxide having the lowest value of Ksp at 25Â°C is
18) The solubility of BaF2 in a solution of Ba(NO3)2 is represented by the concentration term
19) The solubility of Agl in NaI solution is less than that in pure water because
a) AgI forms a complex with NaI
b) Of the common ion effect
c) the solubility product of Agl is less than that of NaI
d) The temperature of the solution decreases
20) The correct representation of the solubility product of SnS2 is
21) When HCl gas is passed through a saturated solution of NaCl, the NaCl is precipitated because
a) The impurities dissolve in HCl
d) The solubility product of NaCl is lowered by the chloride ion from aqueous HCl
22) Precipitation just occurs when the product of the concentration of ions
a) Equals their solubility product
b) Exceeds their solubility product
c) Is less than their solubility product
d) Is negligible.
23) The most soluble salt among the following is
d) All have same solubilities
24) At a certain temperature the value of pKw = 13.4 and the measured pH of a solution is 7. The solution is
25) If the solubility of Ca (OH)2 is 31/2, what will be the solubility product ?
26) The solubility product of AgCl is 1.44 x 10-4 at 373 K. The solubility of AgCl in boiling water will be
27) Which of the following is most soluble ?
28) The concentration of Ag+ ions in a given saturated solution of AgCl is 1.06x 10– 5g ion per litre at 25Â°C. The solubility product of AgCl is
29) Ksp of AgCl at 18Â°C is 1.5 x 10-10. If [Ag+] of solution is 4 x 10-3 mole/litre, the the Cl– ion concentration that must be exceeded before AgCl is precipitated would be
a) 3.75 x 10 -8 mole/litre
30) A saturated solution of calcium fluoride contains 2 x 10-4 moles of the salt per litre of the solution. Its Ksp is
31) When equal volumes of the following solutions are mixed, precipitation of AgCl (Ksp = 1.8 x 10– 10) will occur only with
32) The solubility of AgCl is 0.0015 g/litre. The solubility product of AgCl will be
a) 1.1 x 10-10
b) 2.25 x 10-10
33) The solubility of PbCl2 at 25Â°C is 6.3 x 10-3 mole/litre. The solubility product of PbCl2 at 25Â°C is
34) @ How many grams of CaC2O4 will be present in one litre of saturated solution ? Ksp of CaC2O4 is 2.5 x 10-9 mole-2 and its molecular weight is 128
a) 0.0064 g
b) 0.0128 g
c) 0.0032 g
d) 0.0640 g
35) Which solid is less soluble in 0.5 M HCI than in water ?
36) A physician wishes to prepare a buffer solution at pH = 3.58 that efficiently resists a change in pH yet contains only a small concentration of buffering agents. Which one of the following weak acids together with its sodium salt would be best to use ?
37) @ To 100 mL of 0.1 M AgNO3 solution, solid K2SO4 is added. What is the concentration of K2SO4 at which precipitation will start?( Ksp for Ag2SO4 = 6.4x 10-3M)
a) 0.1 M
b) 6.4 x 10-1 M
38) Ksp = [A]3 [B]2 for the salt where A and B are the cation and anion respectively stands true for
39) Let the solubilities of AgCl in H2O, 0.01 M CaCl2 0.01 M NaCl and 0.05 M AgNO3 be S1, S2, S3 and S4 respectively. What is the correct relationship between these quantities ?
40) A saturated solution of Mg(OH)2 in water at 25Â°C contains 0.11 g Mg(OH)2 per litre of solution. The solubility product of Mg(OH)2 is
41) Ksp for NaCl is 36 mole2/litre2. The molarity of the saturated solutions is
a) 1/36 M
b) 1/6 M
c) 6 M
d) 3600 M
42) The solubility of PbCl2 in water is 0.01 M at 25Â°C. Its maximum concentration in 0.1 M NaCl will be
43) The solubility product of a sparingly soluble salt AB at room temperature is 1.21 x 10– 6. Its molar solubility is
44) If the solubility product of AgBrO3 and Ag2SO4 are 5.5 x 10-5 and 2 x 10-5 respectively, the relationship between the solubilities of these is
45) Which of the following solution cannot act as a buffer ?
46) How many milligrams of AgBr will dissolve in water to give 20 litres of aqueous solution ? Ksp for AgBr (mol.wt = 188) = 5.0 x 10– 13
a) 2.66 mg
b) 1.33 mg
c) 5.32 mg
47) The solubility of AgCl is 0.0014 g. per litre at 18Â°C. What is the solubility product at this temperature. Mol.wt of AgCl is 143.5
48) The solubility of BaSO4 in moles per litre is 1 x 10 -5, its solubility product is
49) What concentration of Ag+ ions will be in equilibrium with a saturated solution containing a precipitate of Ag2CrO4 and CrO4 – ion concentration of 0.40 mole per litre? Ksp of Ag2CrO4=1.1×10-11
50) The solubility of SrF2 at 25Â°C is 1.22 x 10-2 g/litre. What is the solubility product of SrF2 at this temperature ? Mol. wt of SrF2= 125.6 g
51) A solution contains Pb2 + ions. By adding Na2SO4 it is possible to precipitate PbSO4. What concentration is needed to reduce [Pb2+] to 2×10-6 moles per litre ? Ksp of PbSO4 is 1.8×10-8
52) One litre of a saturated solution of CaCO3 is evaporated to dryness. As a result 7.0 mg of residue is left. What is the solubility product of CaCO3 ?
53) A buffer solution can be prepared from a mixture of
a) Sodium acetate and acetic acid in water
b) Sodium acetate and hydrochloric acid in water
c) Ammonia and hydrochloric acid
d) ammonium chloride and hydrochloric acid
54) Equal volumes of 0.02 M CaCl2 and 0.0004 M Na2SO4 are mixed. Will there be any precipitation? Ksp for CaSO4 = 2.4x 10-5
55) In which of the following solvents will AgBr have the highest solubility ?
b) 10-3M NH4OH
c) Pure water
56) If a substance dissolves at saturation with the evolution of heat, the solubility
a) Decreases with an increase in temperature
b) Increases with increase in temperature
c) Does not change
57) If a substance at saturation dissolves with the absorption of heat, the solubility ….. with an increase in temperature.
c) Does not change
58) The solubility of AgCl is 1.435 x 10-3 g/litre. What is the solubility product of AgCl?
Ag = 108, Cl = 35.5.
59) The solubility of AgCl in 0.2 M NaCl solution Rr is which of the following ? Ksp of AgCl = 1.20 x 10-10
60) The solubility product of a sparingly soluble salt AB at room temperature is 1.21 x 10-6. Its
molar solubility is
61) The solubility product (Ksp) of CaF2 is 2 x 10-5. The solubility of CaF2 is
62) The conjugate acid of is
63) Which acts both as a Lowry Bronsted acid and base?
64) Among the following, the compound that does not act as a Lewis acid is
65) Which of these is a Lewis acid?
66) In a decinormal solution, CH3COOH is ionised to the extent of 1.3%. If log 1.3 = 0.11, what is the pH of the solution ?.
c) 4.89 a
67) The strongest base among the following is
To a mixture of CH3COOH and CH3COONa, a further amount of CH3COONa is added.
The pH of the mixture
c) Remains unchanged
69) The equilibrium Cr2O72- CrO42- is shifted to the right in
a) an acidic medium
b) a basic medium
c) a neutral medium
d) It does not exist
70) @ For a reaction, A Products, the rate of reaction doubles when the concentration of A is increased by 4 times. The order of reaction is
71) The minimum amount of energy required by the reacting molecules at the time of collisions in order to produce effective collisions is called the
a) Activation energy
b) Threshold energy
c) Internal energy
d) Potential energy
72) The chemical reactions in which reactants need a high amount of activation energy are generally
c) Very fast
73) The velocity constant for the forward reaction is 10 and the equilibrium constant is 50. The velocity constant of the backward reaction will be
74) Raising the temperature of an equilibrium system
a) Favours the exothermic reaction only
b) Favours the endothermic reaction only
c) Favours both the exothermic and endothermic reaction
d) Favours neither the exothermic nor the endothermic reaction
75) Raising the temperature of a reversible chemical reaction
a) Favours the forward rate only
b) Favours the backward rate only
c) Favours either the forward or backward reaction depending upon the sign of DH
d) Favours neither the forward nor backward rates
76) At high altitudes the boiling point of water lowers because the
a) Atmospheric pressure is low
b) Temperature is low
c) Atmospheric pressure is high
d) Water is cold
Ans 1) a
Ans Desc 1) No. of moles = 64/128 = 0.5. Active mass = 0.5/2 = 0.25 (V = 2 litres)
Ans 2) c
Ans Desc 2) The equilibrium constant is affected by temperature.
Ans 3) b
Ans Desc 3) This reaction will proceed in the forward direction. All the rest occur in the reverse direction
Ans 4) c
Ans Desc 4) Pressure has no effect on those reactions which take place without change in volume
Ans 5) a
Ans Desc 5)
Ans 6) a
Ans Desc 6) The addition of the product causes the equilibrium to shift in the reverse direction (to the left).
Ans 7) c
Ans Desc 7) An increase in the concentration of any reactants always favours the forward reaction and so the equilibrium gets shifted to the right. Similarly a decrease in the concentration of products favours the backward reaction. Hence the reactants and products should be formed at an equal rate.
Ans 8) a
Ans Desc 8) The addition of a reactant causes the equilibrium to shift to the right (forward direction).
Ans 9) b
Ans Desc 9) The reaction is taking place with increase in number of moles or volume.
Ans 10) d
Ans Desc 10) Pressure has no effect on equilibrium of the reaction where Kc = Kp or number of moles of gaseous products = Number of moles of gaseous reactants.
Ans 11) a
Ans Desc 11)
Ans 12) a
Ans Desc 12) Rate = K [pH2S]2 x [pO2] =x.
On increasing the pressure 3 fold,
Rate = K [3pH2S]2 [3pO2] = K x 9pH2S2 x 3pO2
= K x 27 x pH2S2 x pO2 = 27x.
Hence the rate will increase 27 times.
Ans 13) a
Ans Desc 13)
Kc = 20
In order to have Kc = K1 the conc. of C, ie [C] must increase. Thus the reaction should proceed from left to right.
Ans 14) c
Ans Desc 14) The given sulphides are binary. In this case, the smaller the KLsp, the less is the solubility of the salt, because for binary electrolytes S =.
Ans 15) b
Ans Desc 15) The solubilities of MnS, ZnS, Bi2S3 and Ag2S are S2, S2, 105 S5 and 4 S3 respectively.
Ans 16) b
Ans Desc 16) For binary electrolytes, the greater the value of Ksp, the greater is the solubility.
Ans 17) d
Ans Desc 17) The solubility of these hydroxides follows the order
Ba(OH)2 > Ca(OH)2 > Mg (OH)2 > Be (OH)2
Ans 18) c
Ans Desc 18) If s is the solubility of BaF2 in a solution of Ba(NO3)2, then
BaF2 Â« Ba2+ + 2F– or Ksp = [Ba2+] [F–]2.
Thus [F–]=2S or S=Â½[F–]
Ans 19) b
Ans Desc 19) The increase in concentration of I– causes an increase in ionic concentration. [Na+] [I–]. This will cause the backward reaction as Ksp = [Na+] [I–].
Ans 20) a
Ans Desc 20) SnS2 Â« Sn4 + 2S2-;
Ksp = [Sn4+][S2-]2.
Ans 21) c
Ans Desc 21) The increase in concentration of Cl– ions from HCl gas causes an increase in ionic concentration. [Na+] [Cl –]. This will lead to the backward reaction, since Ksp = [Na+] [Cl –]. Thus the product of ionic concentration exceeds the solubility product of NaCl.
Ans 22) a
Ans Desc 22) Precipitation just occurs when the product of ionic concentration becomes equal to the solubility product. This is a limiting case at which precipitation just starts, although precipitation takes place when the ionic product exceeds their solubility product.
Ans 23) c
Ans Desc 23) If various salts have nearly the same Ksp values, the most soluble is that which produces the highest number of ions in solution. Thus Tl3PO4 is most soluble because it gives the maximum number ie, 4 ions in solution.
Ans 24) b
Ans Desc 24) At this temperature pH of the neutral solution will be 13.4/2 = 6.7.
Thus pH greater than 6.7 at this temperature indicates that the solution is basic.
Ans 25) d
Ans Desc 25) Ca(OH)2 Â« Ca2 + + 2OH–;
Ksp = s [2s]2 = 4s3 or 4 3 = Ksp
Or Ksp= 12.
Ans 26) b
Ans Desc 26) AgCl Â« Ag+ + Cl– ; Ksp =ss = s2 or s = [1.44 x 10-4]1/2 =1.2×10-2M.
Boiling water means 100 + 273 = 373 K.
Ans 27) b
Ans Desc 27) For Bi2S3, solubility M
For MnS, solubility = [7 10-16]1/2 = 2.6 10-8M
For CuS, solubility = [8 10-37]1/2 = 8.9 10-19 M
For Ag2S, solunility [610-51] = 1.410-17M.
Ans 28) c
Ans Desc 28) AgCl Â« Ag+ + Cl–; Ksp = s s = s2.
[Ag+] = 1.06 10-5, so [Cl] = 1.06 10-5.
Thus Ksp = [1.06 10-5]2 = 1.12 10-10
Ans 29) d
Ans Desc 29) Ksp = [Ag+] [CI–] or 1.8 x 10-10
=4.5x 10-8 mole/litre.
Ans 30) b
Ans Desc 30) CaF2 Â« Ca2 + 2F–
Ksp = s x [2s]2 = 4s3
= 4x(2x 10-4)3 = 3.2×10-11
Ans 31) a
Ans Desc 31) AgCl Â« [Ag+] [CI–]
This value is greater than Ksp = 1.8 x 10-10
Ans 32) a
Ans Desc 32) For AgCl, Ksp = s x s = s2
Ans 33) c
Ans Desc 33) PbCl2 Â« Pb2+ + 2CI– = 6.3 x 10– 3.
Now Ksp = (6.3 x 10– 3) (2 x 6.3 x 10-3)2
= (6.3x 10-3)(12.6×10-3)2
Ans 34) a
Ans Desc 34) s = [Ksp]1/2 = [2.5 x 10-9]1/2 = 5x 10– 5 mole/litre.
Thus or w = 6.4 x 10– 3 g = 0.0064 g.
Ans 35) b
Ans Desc 35) Solubility of Hg2Cl2 decreases in presence of HCl because of common Cl– ions.
Ans 36) d
Ans Desc 36)
pH = pKa + log[Salt]
or 3.58 = 3.58.+.
When [Salt]= [Acid], pH=pKaor 3.58=3.58
Ans 37) b
Ans Desc 37) Ksp =[Ag+] 2[SO42-].
Thus [SO42-] = = 6.4 x 10 – 3M.
Ans 38) a
Ans Desc 38) In the first case, Ksp = [A2+]3 [B3-]2
Ans 39) c
Ans Desc 39)
Ans 40) d
Ans Desc 40) For Mg (OH)2 Â« Mg2 + + 2OH–;
Ksp = [s] [2s]2 = 4s3 also s = mole/litres.
Ans 41) c
Ans Desc 41) s = [Ksp]1/2 = 1/2 = 6M
Ans 42) d
Ans Desc 42) PbCl2 Â« Pb2 + 2CI–
Ksp = 4s3 = 4 x (0.01)3 =4×10– 6.
In NaCl solution, Ksp = [Pb2+] [Cl–]
or4x10-6 = [Pb2+][0.1]2
Ans 43) d
Ans Desc 43) s = [Ksp]1/2=[1.21 x 10-6]1/2
Ans 44) b
Ans Desc 44) For Ag2SO4, K = 4s3 or
For AgBr03,Ksp = s2 or s = [Ksp]1/2 = [2×10-5]1/2=4.4×10-3M
Ans 45) c
Ans Desc 45) Because it is a mixture of a strong acid (HCl) and a weak base (NH4OH).
Ans 46) a
Ans Desc 46) Ksp= s2 or s2 =50 x 10-14 or s = 7.071×10-7 moles/litre.
Solubility= 7.071 x 10– 7 x 20 x 188 x 1000 mg /20 litres = 2.66 mg/20 litres.
Ans 47) a
Ans Desc 47) Solubility in moles = 0.0014/143.5 = 0.9757 x10-5.Ksp = s x s = s2
= [0.9757 x 10-5]2 = 0.952 x 10-10
Ans 48) a
Ans Desc 48) Solubility s = 2.33 x 10-4 g/10OmL = 2.33 x10-3g/litre. Thus
s = 2.33 x 10-3/233 = 1 x 10-5 moles/litre. Ksp = [1 x 10-5]2 = 1 x 10– 10 moles/litre.
Ans 49) c
Ans Desc 49) [Ag+]2 [CrO42-] = Ksp= 1.1 x 10-11 = [Ag+] [0.40].
Thus [Ag+] 2=27.5×10-12
[Ag+] = 5.2 x 10– 6 moles/litre.
Ans 50) b
Ans Desc 50) Molar solubility of SrF2 = = 9.712 x 10-5 moles/litre.
Ksp = 4s3 = 4 x [9.712 x 10-5]3 = 3.66 x 10-12
Ans 51) b
Ans Desc 51) Ksp = [Pb2+] [SO42-] or [SO42-] =
Ans 52) a
Ans Desc 52) The solution contains 7.0 mg CaCO3 = 7 x 10-3 g.
Mole concentration of CaCO3 = 7×10-3 g
Ksp = [Ca2+] [CO32-] = s x s = s2=[7.0x 10-5]2
Ans 53) a
Ans Desc 53) CH3COOH + CH3COONa (acidic buffer)and NH4OH + NH4Cl (basic buffer)
Ans 54) b
Ans Desc 54)
Suppose V mL of both are mixed.
Since ionic concentration (2×10-6) is less than the solubility product (2.4×10-5), CaSO4 will not be precipitated.
Ans 55) b
Ans Desc 55) AgBr forms a soluble complex with NH4OH, i.e., [Ag(NH3)2] Br.
Ans 56) a
Ans Desc 56)
Ans 57) b
Ans Desc 57) Self explanatory
Ans 58) b
Ans Desc 58) Solubility in moles per litre
= moles per litre
Ksp = s x s = s2 = [l x 10-5]2= 1 x 10-10.
Ans 59) d
Ans Desc 59) Ksp = [Na+] [Cl–]= 1.2 x 10– 10= [s] [0.2]
Ksp= s 0.2 = 1. 2 10-10 or s =
Ans 60) d
Ans Desc 60) s==
= 1.1 x 10-3 moles/litre.
Ans 61) b
Ans Desc 61) Ksp =lx10-11=4s3
s = 1/3x104 moles/litre
= 2.2 x 10-4 moles/litre
= 2.2 x 10-4 x 78 = 0.017 g. litre-1 (Mol. wt of CaF2 = 78)
Ans 62) a
Ans Desc 62) + H+ NH3 (conjugate acid).
Ans 63) d
Ans Desc 63) can accept a proton to form H2SO4 and it can donate a proton to form ion.
Ans 64) c
Ans Desc 64) NH3 acts as a Lewis base.
Ans 65) d
Ans Desc 65) BF3 is an electron deficient compound having 6 electrons on the Boron atom. It can accept a lone pair of electrons.
Ans 66) b
Ans Desc 66) The solution is decinormal, that is, M/10. Thus
[H+] = c x a = 10-1 x 1.3 x 10-2 M.
pH = 3.0 – 0.11 = 2.89.
Ans 67) a
Ans Desc 67) The conjugate acid of CH is CH4, which is almost neutral. So its conjugate base CH is strongest.
Ans 68) a
Ans Desc 68) The pH will increase , because pH = -log Ka = log
The pH increases as the salt concentration increases.
Ans 69) b
Ans Desc 69)
Ans 70) c
Ans Desc 70)
Ans 71) b
Ans Desc 71)
Ans 72) b
Ans Desc 72)
Ans 73) a
Ans Desc 73)
Ans 74) b
Ans Desc 74)
Ans 75) c
Ans Desc 75)
Ans 76) a
Ans Desc 76)