Chemical eqiulibrium

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1If one mole of gaseous hydrogen is mixed with one mole of gaseous iodine in an empty container then with the passage of time( )Rate of forward reaction increases

( )Rate of both forward and reverse reaction remains unaffected

( )Rate of reverse reaction decreases

( )Rate of forward reaction decreases

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2Equilibrium constant expression for the reaction P4(s) + 6Cl2(g)4PCl3(l) is( )Kc=[PCl3]^4/[P4][Cl2]^6

( )Kc=[P4[Cl2]^6/[PCl3]^4

( )Kc=1/[Cl2]^6

( )Kc=[Cl2]^6

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3For a gaseous eqiulibrium all of the following combinations are incorrect except( )When dn=0, Kp>Kc

( )When delta n = positive, Kp2C + 2D. Which of the following statement is not correct/( )The rate of disappearance of B is one fourth the rate of disappearance of A

( )The rate of appearance of C is one half of the rate of disappearance of A

( )The rate of disappearance of C is one half the rate of consumption of A

( )The rate of formation of C and D are equal

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111Considering the reaction 2SO2 + O2------->2SO3, dH=-ve, the yield of SO3 will be maximum if( )Temperature iss increased, pressure is kept constant

( )Temperature is reduced, pressure increased

( )Temperature and pressure are both increased

( )Temperature and pressure are both decreased

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112PCl5(g)PCl3(g) + Cl2(g); dH=+ve. The concentration of Cl2 at equilibrium will be increased by( )Lowering temperature

( )Adding PCl3 to the mixture

( )Adding PCl5 to the mixture

( )Increasing the pressure

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113For the reaction H2(g) + I2(g)2HI(g). The equilibrium constant changes with( )Catalyst

( )Total amout of H2 and I2

( )Temperature

( )Total pressure

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114The ionization of NH4OH is suppressed by adding( )NaCl

( )HCl

( )NH4OH

( )NH4Cl

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115The formation of NO2 at equilibrium in the reaction 2NO + O22NO2 + heat should be favoured by( )High temperature, high pressure

( )Low temperature, ow pressure

( )Low temperature, high pressure

( )High temperature

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116The concentration of HI, H2 and I2 at equilibrium in the reaction H2 + I22HI are 10, 5, 5 mol/L respectively. The value of equilibrium constant is( )4

( )10

( )100

( )5

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117The dynamic equilibrium is the state of a reversible chemical reaction at which the rate of reverse reaction at the given conditions of temperature and pressure and rate of forward reaction are( )Equal

( )Less

( )More

( )Changes constantly

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118The energy required in addition to average energy of reactants to convert them into products is called( )Enthalpy function

( )Heat of reaction

( )Effective energy

( )Activation energy

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119The value of Kc( )Does not change with the increase in temperature

( )Changes with change of temperature

( )Does not change with the decrease in temperature

( )None of these

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120Solubility product( )Is not for sparingly soluble ionic compounds

( )Is for sparingly soluble ionic compounds

( )Is useful for soluble ionic compounds

( )None of these

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121When the system H2(g) + Cl2(g)2HCl(g) is in equilibrium at 400 C at 1 atm, the value of Kp is 10. What will be the value of Kp at 2 atm at 400C?( )40

( )20

( )10

( )5

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122Consider reaction A(aq) + B(aq)2C(aq) + D(aq). In a certain mixture, the equilibrium concentrations of B is 10 mol/L. What will be the new equilibrium concentration of B if 5 mol of pure B is added to the mixture?( )15 mol/L

( )Between 10 to 15 mol/L

( )Between 5 to 10 mol/L

( )5 mol/L

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123Why is ethanoic acid a stronger acid in liquid ammonia than in water?( )Ethanoic acid molecules form H-bond with water

( )Ethanoate ions form H-bond in water

( )Ethanoic acid is more soluble in ammonia than in water

( )Ammonia is a stronger base than water

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124The value of Kc for a reaction at equilibrium at T C( )Depends upon initial concentrations

( )Depends upon equilibrium concentrations of products and reactants

( )Is not characteristic of the reaction

( )Depends upon initial concentrations of reactants only

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125In reaction N2O42NO2 temperature remaining the same, removal of N2O4 will cause( )The reaction rate to increase in the backward direction

( )The reaction rate to increase in forward direction

( )No change in either reaction rate

( )Increase in both the reaction rates

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126What is meant by a very large Kc value?( )Very small amount of reactants have changed into products

( )Almost 50% reactants have changed into products

( )Almost all the reactants have changed into products

( )Concentration of reactants have not changed during reaction

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127In water only a small number of molecules of weak electrolytes are( )Dissolved

( )Ionized

( )Precipitated

( )Unionized

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128With which of the following Kc vaues, reaction goes further to complete( )10^5

( )10^25

( )10^0.5

( )10^1/2

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129At 500K the equilibrium constant for reaction cis-C2H2Cl2trans-C2H2Cl2 is 0.6. At the same temperature, the equilibrium constant for the reaction trans-C2H2Cl2cis-C2H2Cl2 will be( )0.60

( )1.67

( )0.66

( )2.6

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130In a reversible chemical reaction having two reactants in equilibrium, if the concentration of the reactants are doubled then the equilibrium constant will( )Also be doubled

( )Be halved

( )Becomes one fourth

( )Remains the same

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131A chemical reaction AB is said to be at equilibrium when( )Complete conversion of A to B has taken place

( )Conversion of A to B is only 50% complete

( )Only 10% conversion of A to B has taken place

( )The rate of transformation of A to B is just equal to rate of transformation of B to A

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132For the reaction 2A(g) + B(g)3C(g) + D(g) two moles each of A and B were taken into a flask. The following must always be true when the system attained equilibrium( )[A]=[B]

( )[A][B]

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133In a chemical reaction N2 + 3H22NH3 at equilibrium point( )Equal volumes of N2 and H2 are reacting

( )Equal masses of N2 and H2 are reacting

( )The reaction has stopped

( )The same amount of ammonia is formed as is decomposition into N2 and H2

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134According to Le-Chatelier's principle, adding heat to a solid and liquid in equilibrium will cause( )Amount od solid to decrease

( )Amount of liquid to decrease

( )Temperature to rice

( )Temperature to fall

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135Which of the following factors will favour the reverse reaction in a chemical equilibrium?( )Increase in concentration of one of the reactants

( )Increase in the concentration of one of the products

( )Removal of one of the products regularly

( )None of these

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136The active mass of 64g of HI in two litre flask would be( )2

( )1

( )5

( )0.25

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137Two moles of HI was heated in a sealed tube at 440 C till the equilibrium was reached. HI was found to be 22% decomposed. The equilibrium constant for dissociation is( )0.282

( )0.0796

( )0.0199

( )1.99

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1384 moles of A are mixed with 4 moles of B, when 2 moles of C are formed at equilibrium according to the reaction A+BC+D. The value of equilibrium constant is( )4

( )1

( )1/2

( )1/4

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139For a reaction H2 + I22HI at 721 K, the value of equilibrium constant is 50. If 0.5 moles each of H2 and I2 is added to the system the value of equilibrium constant will be ( )0.02

( )0.2

( )50

( )25

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140The factor which changes equilibrium constant of the reactio A2(g) + B2(g)2AB(g) is( )Total pressure

( )Amounts of A2 and B2

( )Temperature

( )Catalyst

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141At certain temperature, 50% of HI is dissociated into H2 and I2, the equilibrium constant is( )1.0

( )3.0

( )0.5

( )0.25

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1421.1 mol of A is mixed with 2.2 mol of B and the mixture is kept in one litre flask till the equilibrium is reached. At equilibrium, 0.2 mol of C is formed. If the equilibrium reaction is A + 2B2C +D, the value of equilibrium constant is( )0.002

( )0.004

( )0.001

( )0.003

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143The equilibrium constant Kp for the reaction PCl5(g)PCl3(g)+Cl2(g) is 16. If the volume of the container is reduced to half of its original volume, the value of Kp for the reaction at the same temperature will be( )32

( )64

( )16

( )4

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144In a reaction A+2B2C, 2.0 moles of "A" 3 moles of 'B' and 2 moles of 'C' are placed in a 2 L flask and the equilibrium concentration of 'C' is 0.5 mol/L. The equilibrium constant for the reaction is( )0.073

( )0.147

( )0.05

( )0.026

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145The concentration of reactants is increased by x, then the equilibrium constant K becomes( ) lnK/x

( )K/x

( )K+x

( )K

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146A chemical reaction AB is said to be at equilibrium when( )Complete conversion of A to B has taken place

( )Conversion of A to B is only 50% complete

( )Only 10% conversion of A to B has taken place

( )The rate of transformation of A to B is just equal to rate of transformation of B to A in the system

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147For the reaction 2A(g) + B(g) 3C(g) + D(g) two moles each of A and B were taken into a flask. The following must always be true when the system attained equilibrium( )[A]=[B]

( )[A][B]

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148In a chemical reaction N2+3H22NH3 at equilibrium point( )Equal volumes of N2 and H2 are reacting

( )Equal masses of N2 and H2 are reacting

( )The reaction has stopped

( )The same amount of ammonia is formed as is decomposed into N2 and H2

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149The active mass of 64g of HI in a two litre flask would be( )2

( )1

( )5

( )0.25

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150Two moles of HI was heated in a sealed tube at 440 C till the equilibrium was reached. HI found to be 22% decomposed. The equilibrium constant for dissociation is( )0.282

( )0.0796

( )0.0199

( )1.99

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151The state of equilibrium refers to( )State of rest

( )Dynamic state

( )Stationary state

( )State of inertness

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1524 moles of A are mixed with 4 moles of B, when 2 moles of C are formed at equilibrium according to the reaction A+BC+D. The value of equilibrium constant is( )4

( )1

( )1/2

( )1/4

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153For a reaction H2+I22HI at 721 K, the value of equilibrium constant is 50. If 0.5 moles each of H2 and I2 is added to the system the value of equilibrium constant will be( )0.02

( )0.2

( )50

( )25

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154In which of the following cases , the reaction goes farthest to completion( )K=10^3

( )K=10^-2

( )K=10

( )K=10^0

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155In an exothermic reaction, a 10 degree rise in temperature will( )Decrease the value of equilibrium constant

( )Double the value of Kc

( )Not produce any change in Kc

( )Produce some increase in Kc

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156The factor which changes equilibrium constant of the reaction A2(g)+B2(g)2AB(g) is( )Total pressure

( )Amounts of A2 and B2

( )Temperature

( )Catalyst

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157At constant temperature, 50% of HI is dissociated into H2 and I2 the equilibrium constant is( )1.0

( )3.0

( )0.5

( )0.25

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1581.1 mol of A is mixed with 2.2 mol of B and the mixture is kept in one litre flask till the equilibrium is reached. At equilibrium 0.2mol of C is formed. If the equilibrium reaction is A+2B2C+D, the equilibrium constant is( )0.002

( )0.004

( )0.001

( )0.003

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159The equilibrium constant Kp for the reaction PCl5(g)PCl3(g) + Cl2(g) is 16. If the volume of the container is reduced to half of its original volume, the value of Kp for the reaction at the same temperature will be( )32

( )64

( )16

( )4

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160In a reaction A+2B2C, 2.0 moles of A 3 moles of B and 2.0 moles of C are placed in a 2.0L flask and the equilibrium oncentration of C is 0.5 mol/L. The equilibrium constant for the reaction is( )0.073

( )0.147

( )0.05

( )0.026

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161In a reversible reaction, two substances are in equilibrium. If the concentration of each one is reduced to half, the equilibrium constant will be( )Reduced to half of it original value

( )Doubled

( )Same

( )Reduced to one fourth its original value

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162The concentration of reactants is increased by x, then equilibrium constant K becomes( ) lnK/x

( )K/x

( )K+x

( )K

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163In a reaction A+BC+D, the initial concentrations of A and B were 0.9 mol/dm3 each. At equilibrium the concentration of D was found to be 0.6 mol/dm3. What is the value of equilibrium constant for the reaction?( )8

( )4

( )9

( )3

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164For the reaction PCL5(g)PCl3(g)+Cl2(g) the forward reaction at constant temperature is favoured by( )Introduction of an inert gas at constant volume

( )Introduction of PCl3(g) a constant volume

( )Introduction of PCl5(g) at constant volume

( )Introduction of Cl2(g) at constant volume

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1654.5 moles each of hydrogen and iodine heated in a sealed ten litre vessel. At equilibrium 3 moles of HI were found. The eqiulibrium constant for H2(g)+I2(g)2HI(g) is ( )1

( )10

( )5

( )0.33

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1663 moles of A and one mole of B are mixed in a vessel of volume 1L. The reaction taking place is A+B2C. If 1.5 mol of C is formed at equilibrium, the value of Kc is( )0.12

( )0.50

( )0.25

( )4.00

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167For the reaction 2HIH2+I2( )Kp>Kc

( )Kc>Kp

( )Kp=Kc

( )None of these

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168A gas bulb is filled with NO2 gas and immersed in an ice bath at 0 C which becomes colourless after sometime. This colourless gas will be( )NO2

( )N2O

( )N2O4

( )N2O5

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169When H2 and I2 are mixed and equilibrium is attained, then( )Amount of HI formed is equal to the amount of H2 dissociated

( )HI dissociation stops

( )The reaction stops completely

( )None of these

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1701 mole of hydrogen and 2 moles of iodine are taken initially in a 2L vessel. The number of moles of hydrogen at equilibrium is 0.2. Then the number of moles of iodine and hyfrogeniodide ar equilibrium are( )1.2,1.6

( )1.8,1.0

( )0.4,2.4

( )0.8,2.0

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1711 mole of N2 and 2 moles of H2 are alloqed to react in a 1dm3 vessel. At equilibrium 0.8 moles of NH3 is formed. The concentration of H2 in the vessel is( )0.6 mole

( )0.8 mole

( )0.2 mole

( )0.4 mole

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172The rate of forward reaction is two times that of the reverse reaction at a given temperature and identical concentration, K equilibrium is( )0.5

( )1.5

( )2.5

( )2.0

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173For a reaction if Kp>Kc, the forward reaction is favoured by (T>15 K)( )High temperature

( )Low temperature

( )Low pressure

( )High pressure

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174In a lime kiln, to get higher yield of CO2, the measure that can be taken is( )To maintain high temperature

( )To pump out CO2

( )To remove CaO

( )To add more CaCO3

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175Which of the following is a characteristic of a reversible reaction?( )It never proceeds to completion

( )It can be influenced by a catalyst

( )It proceeds only forward direction

( )Number of moles of reactants and products are equal

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176Ammonium carbonate when heated to 200 C gives a mixture of NH3 and CO2 vapour with a density of 13.0. What is the degree of dissociation of ammonia carbonate?( )3/2

( )1/2

( )2

( )1

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177A quantity of PCl5 was heated in a 10 L vessel at 525 K. PCl5(g)PCl3(g)+Cl2(g). At equilibrium the vessel contains 0.10 mol of PCl5, 0.2 mol of PCl3 and 0.2 mol of Cl2. The equilibrium constant for the reaction is

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178For the reaction, C(s)+CO2(g)2CO(g), the partial pressure of CO2 and CO are 2.0 and 4.0 atm at equilibrium. The Kp for the reaction is

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179Which will not change conc. of ammonia at equilibrium?( )Increase in P

( )Increase in V

( )Decrease in T

( )Addition of catalyst

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180In which of the following equilibria will Kc and Kp have the same value?( )PCl5PCl3+Cl2

( )N2+3H22NH3

( )2CO+O2CO2

( )N2+O22NO

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181Which of the following gaseous equilibria, the equilibrium will shift to the right if total pressure is increased( )N2+3H22NH3

( )N2O42NO2

( )H2+Cl22HCl

( )N2O42NO2

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182Which of the following is not favourable for the formation of SO3? 2SO2(g)+O2(g); dH=-188 kJ( )High pressure

( )High temperature

( )Decreasing [SO3]

( )Increasing [SO2]

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183The value of standard free energy for a reaction having K=1 would be

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184At 90 degree Celsius water has [H3O+] = 10^-6 mol/L. What is the value of Kw at 90 degree Celsius

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185 pH of an aqueous solution is 5.5. The hydroxyl ion conc. in the solution would be

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186Ksp for a substance XY is 10^-2 mol^2/L^2. Molecular mass of the substance is 100. Its solubility would be (in g/L)

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187Which of the following is not a Lewis base?( )CH3-

( )AlCl3

( )R-OH

( )RNH2

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188Which one of the following is not amphipratic( )HSO4-

( )HCO3-

( )H2PO4-

( )HCOO-

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189The ionic product of water changes when( )An acid is added to it

( )A base is added to it

( )Either a base or an acid is added to it

( )Temperature is raised

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190The conjugate base of HCO3- is

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191The conjugate acid of HSO3- is

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192 pH of 0.005 M aqueous solution of H2SO4 is nearly

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193The compoudn that is not a Lewis acid is( )BF3

( )AlCl3

( )NF3

( )SnCl4

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194If Ka=10^-5 for a weak acid, then pKb for its conjugate base would be

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195Which of the following equimolar solutions can act as an acidic buffer( )NH4Cl and NH4OH

( )HCl and NaCl

( )HCOOH and HCOONa

( )HNO3 and NH4NO3

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196Which of the following has highest pH( )Distilled water

( )1 M NH3

( )1 M NaOH

( )Water saturated with chlorine

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197 Solubility of Fe(OH)3 is x mol/L. Its Ksp would be ( in terms of x)

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198Ksp of sparingly soluble salt Ag2CrO4 is 4 x 10^-12. The solubility of the salt is (in mol/L)

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199PH of a solution is 4. The [OH-] of the solution is (in mol/L)

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