Equilibrium Questions and Answers

arboxylic acids are weak acids and dissociate in water What species is formed by the dissociation of benzoic acid in aqueous solution A benzene B benzoate ion C benzaldehyde D phenol E toluene

The rapid change of pH near the stoichiometric point of an acid base titration is the basis of indicator detection pH of the solution is related to ration of the concentrations of the conjugate acid HIn and base In forms of the indicator by the expression Hin In Hin pH PK In O log O jog pkin pH log pH pKin In Hin log In THinl pk In pH

1 2 4 4 h 3 4 4 Solubility product K of saturated PbCl in water is 1 8 10 mol dm What is the concentratio of Pb in the solution 1 0 45 10 mol dm 3 0 9 10 mol dm 2 1 8 10 mol dm 4 2 0 10 mol dm

A sample of gas contains 0 1000 mol of HBr g and 5 000 102 mol of Cl R and occupies a volume of 7 23 L The following reaction takes place 2HBr g Cl g 2HCl g Bry Calculate the volume of the sample after the reaction takes place assuming that the temperature and the pressure remain constant

1 Sodium hydroxide NaOH is used to titrate benzoic acid C6H5COOH which has a pka of 4 19 Would methyl orange be a good indicator to use for this titration Explain why or why not 2 A new indicator was found at pH values less than 7 5 the indicator is blue and at values greater than 9 5 it is grey What is the approximate pka for this indicator

a 1 b 2 c 3 d 4 B When sulphur is heated at 900 K S is converted to S What will be the equilibrium constant for the reaction if initial pressure of 1 atm falls by 25 at equilibrium a 0 75 atm c 25 0 atm b 2 55 atm d 1 33 atm 26 In b

4 A buffer solution made up of BOH and BCI of total molarity 0 29 M has pH 9 6 and Kb 1 8 Concentration of salt and base respectively is A 0 09 M and 0 2 M C 0 1 M and 0 19 M B 0 2 M and 0 09 M D 0 19 M and 0 1 M

3 4 In a 10 litre box 2 5 mole hydroiodic acid is taken After equilibrium 2H1 H 1 the concentration of HI is found to be 0 1moll The concentration of H at equilibrium in mol L is 4 7 5 10 1 2 4 2 0 15 3 1 5

a The heat of reaction A H for the formation of NH3 according to the reaction N 3H 2NH3 at 27 C was found to be 91 94 kJ What will be AH at 50 C The average molar heat capacities at constant pressure and between 27 C and 50 C for N H2 and NH3 are 28 45 28 32 and 37 07 J respectively

Ex 15 25 mL of hydrogen and 18 mL of iodine when heated in a closed container produced 30 8 mL of HI at equilibrium Calculate the degree of dissociation of HI at the same temperature Solution In this problem volume of the species is proportional to their concentration Thus

3 Both Tollen s reagent and Fehling solution 4 None of these Given that the equilibrium constant for the reaction 250 g O2 g 250g has a value of 278 at a particular temperature What is the value of the equilibrium constant for the following reaction at the same temperature SO SO g 1 1 8 10 2 8 2 3 6x10 3 6 0x10 4 1 3x10

The boiling point of an aqueous solution of a non volatile solute is 100 15 C What is the freezing point of an aqueous solution obtained by diluting the above solution with an equal volume of water 11 for water K 0 512 K 1 86 1 0 544 2 0 512 C

is at d aA bB cC dD K K 17 1 mole of NO and 1 mole of O are taken in a 10 L vessel and heated At equilibrium 50 of NO by mass reacts with O according to the equation NO ONO2 O What will be the equilibrium constant for this reaction a 1 b 2 c 3 d 4 25 26 D

1 Following limiting molar conductivities are given as Am H SO4 x S cm mol 1 Am K SO4 y S cm mol 1 zS cm mol 1 NEET Odisha Am CH COOK A m in S cm mol 1 for CH3COOH will be a x y 2z b x y z c x y z x y

The solubility of Cul2 s Ksp 1 1 x 10 12 in 0 15 M Nal aq solution is S 7 33 x 10 12 M S 1 35 x 10 6 M S 4 89 x 10 11 M 1 Ksp S S 0 15 2 Ksp S 0 15 25 2 3 Ksp S 25 0 15 S Ksp 0 15 S Ksp 0 6 1 2 S Ksp 0 15 2

A mixture of 4 76e 02 mol of C2H6 1 41e 02 mol of N2 1 14e 02 mol of NH3 and 2 46e 02 mol of C2H4 is placed in a 1 0 L steel pressure vessel at 1624 K The following equilibrium is established 3 C2H6 g N2 g 2 NH3 g 3 C2H4 g At equilibrium 7 41e 03 mol of NH3 is found in the reaction mixture Calculate the equilibrium pressures of all gases in the reaction vessel and the value of KP for the

CH NH 0 12 mole pK 3 3 is added to 0 08 moles of HCl and the solution is diluted to one litre resulting pH of solution is 1 10 7 2 3 6 3 10 4 4 11 3 64 g non volatile solute is added to 702 g benzene The vapour pressure of benzene has decreased from 200 mm of Hg to 180 mm of Hg Molecular weight of the solute is 1128 2161 3196 41256

Consider the following reactions 2 i CO3 H O ii CO H 0 H CO3 iii NH3 H 0 NH OH iv HCl H O Cl H O HCO3 OH Which of the pairs of reactions proves that water i amphoteric in character a i and ii c iii and iv b ii and iii d i and iii

101 Enthalpy of CH 02CH OH is negative If enthalpies of combustion of CH4 and CH3OH are x and y respectively then which of the following relations is correct a x y c x y 4 1 b x y d x p AMIL Med 11

All the above statements are correct The correct order of the bond dissociation energies of various C H bonds present in the compound is 1 a B y 0 2 3 a 0 B Y Calculate the number of oxygen atoms required to combine with 7g of N to form N O when 80 2 a y 0 B 4 B a 0

24 To a 25 mL H O2 solution excess of acidified solution of potassium iodide was added The iodine liberated required 20 mL of 0 3 N sodium thiosulphate solution Calculate the volume strength of H O2 solution Express your answer in millilitre

Which one of these statements about strong acids is true Select one O a The conjugate base of a strong acid is itself a strong base O b Strong acids produce solutions with a higher pH than weak acids O c Strong acids react completely with water to become 100 ionized Od Strong acids are very concentrated acids e All strong acids have H atoms bonded to electronegative oxygen atoms

B H are longer but stronger 2 I II and IV 1 I II and III 6 The addition of NH CI to 0 1 M acetic acid will cause bond 1 Increase in its pH value 2 Decrease in its pH value 3 No change in its pH value 4 Unpredictable change in its pH value norm 3 I II III and IV onds 4 Only II

3 Conductivity of a saturated solution of a sparingly soluble salt AB at 298 K is 1 85 x 10 5 Sm Solubility product of the salt AB at 298 K is Given A AB 140 104 Sm mol a 5 7 x 10 2 b 1 32 x 10 12 c 7 5 x 10 12 d 1 74

An aqueous solution of 6 3 g of oxalic acid dihydrate is made up of to 250 ml The volume of 0 1 N NaOH required to completely neutralise 10 ml of this solution is A 40 ml C 10 ml B 20 ml D 4 ml

0 5 mole of HCI and 1 0 mole of CH3COONa are added to water and the volume was made up to 1 litre What is the H ion concentration of the resultant solution Ka for CH3COOH is 1 6 10 5 A B C D 4 6 x 10 5 4 x 10 3 0 0042 1 6 x 10 5

is 8 x 10 cm Hence Ksp of BaSO4 is 4x 10 M 2 1 x 10 M 3 2 10 M K 8X10 K eq 400 M 8 105

5 Assertion pH of a buffer solution does not change on dilution Reason On dilution the ratio of concentration of salt and acid or base remains unchanged

H S is bubbled into a 0 4 M NaCN solution which is also 0 04 M in each Ag CN and Cd CN 4 2 Ksp Ag2S 10 50 Ksp CdS 7 1 10 28 K Ag CN 10 20 and K Cd CN 412 7 8 x 1018 Which of the following is incorrect CdS will precipitate first Concentration of S2 when Ag2S will precipitate is 1 6 10 9 M Concentration of S2 when CdS will precipitate is 5 76 10 1 M Ag S will precipitate first

Question Number 68 Question Id 9046847157 Question Type MCQ Option Shuffling Yes Is Question Mandatory No Correct Marks 1 Wrong Marks 0 The decomposition of NO is an endothermic process A sample of NO2 contained in a vessel at constant volume is heated at a temperature of t C to attain equilibrium 2NO2 g 2NO g O2 g The equilibrium pressure changed by 35 What will be the mole fraction of NO at equilibrium Options 90468423852 0 20 90468423853 0 26 90468423854 0 52 90468 22955

In the reaction COCI g CO g Cl g at 550 C when the initial pressure of CO Cl are 250 and 280 mm of Hg respectively The equilibrium pressure is found to be 380 mm of Hg Calculate the degree of dissociation of COCI at 1 atm What will be the extent of dissociation when N at a pressure of 0 4 atm is present and the total pressure is 1 atm A 0 32 and no change C 0 4 and 0 3 B 0 32 and 0 4 D In presence of N dissociation cannot take place

d Between 6 and 7 15 Which of the following options will be correct for the stage of half completion of the reaction AB a AG 0 b AG 0 C AG 0 d AG RT In K 19

DH for the reaction IF5 g IF 3 g F2 g is KJ Given the data below IF g F g IF 3 g IF g 2 F g IF5 g Select one a 35 Ob 35 O c 1135 Od 1135 Oe 355 DH 390 kJ DH 745 kJ

Which one of the following solutions will have the greatest concentration of hydroxide ion Select one O a 0 368 M calcium hydroxide O b 1 10 M rubidium hydroxide O c 0 368 M potassium hydroxide O d 0 368 M Sulfuric acid O e 0 368 M ammonium hydroxide

Review the pK data of the following equilibria and point out which buffer is to be used to study the hydrolysis of methyl acetate at pH 9 25 cy 1 HSO SO2 H pK 1 92 2 H PO HPO2 H pK 7 21 3 CO aq H O HCO3 H pK 6 37 4 HCO3 CO3 H pK 10 25 X 21

D 3 d 5 C 1 37 Equivalent weight of Mn in the following reaction is Mn 55 Mn Mn MnO 3 a 27 5 c 110 b 55 d 165

Pb Cu Zn and Ni ions are present in a given acidic solution On passing hydrogen sulphic gas through this solution the available precipitate will contain 1 PbS and Nis 2 PbS and CuS 3 CuS and ZnS 4 CuS and Nis

RH ion exchange resin can replace Ca2 ions in hard water as RH Ca2 RCA 2H If 1 L of hard water after passing through RH has pH 3 then hardness in parts per million of Ca2 is A B 10 ppm Your Answer 40 ppm

The Ksp of Cu OH is 4 8x10 20 Determine the molar solubility of Cu OH 2 in a buffer solution with a pH of 10 1 Select one O a 3 8 x 10 16 mol L O b 2 2 x 10 10 mol L O c 3 0 x 10 12 O d 3 0 x 10 2 mol L Of 60x10 10 mol l gram mL

9 Log K P Bo log RT 0 This relationship is valid for which reaction a PCI b 2SO 0 g g c H 1 g g PCI Cl g g 2SO3 g 2HI d N 3H 2NH g 16

1 We know that the relationship between K and K is P 2 K K RT An P C What would be the value of An for the reaction g NH Cl s NH3 g HCl g a 1 c 1 5 For the reaction b 0 5 d 2 6

61 At certain temperature dissociation constant of formic acid and acetic acid are 1 8 x 104 and 1 8 x 10 5 respectively At what concentrations of acetic acid solution the H O ion concentration is same as that in 0 001 M formic acid solution a 0 01 M b 1 x 10 M c 1 x 10 M d 1 x 104 M W

A student determines the value of the equilibrium constant to be 1 06 106 for the following reaction 3Fe O3 s H g 2Fe3O4 s H O g Based on this value of Keqi AGO for this reaction is expected to be greater less Calculate the free energy change for the reaction of 2 30 moles of Fe O3 s at standard conditions at 298K kJ AGO Ixn than zero

HW 103 The temperature at which a first order reaction with activation energy 919 5 kJ and Arrhenius factor of 1012 s will have a half life period of 693 second is b 1000 K d 333 3 K a 666 7 K c 1555 5 K

d Bronsted Lowry as well as Lewis concept 11 Which of the following will produce a buffer solution when mixed in equal volumes a 0 1 mol dm NH OH and 0 1 mol dm HCl b 0 05 mol dm NH OH and 0 1 mol dm HCl c 0 1 mol dm NH OH and 0 05 mol dm HCl d 0 1 mol dm In which of the CH COONa and 0 1 mol dm NaOH following solvents is silvor

Dissociation of phosphorus pentachloride is favoured by 1 High temperature and high pressure 2 High temperature and low pressure 3 Low temperature and low pressure 4 Low temperature and high pressure 22 dichloro propane on hydrolysis vields

33 The minimum concentration of silver ions that is required to start the precipitation of Ag S K 10 in sp a 0 1 M solution of S is a 10 4 M c 10 26 M b 10 50 M d 10 25 M

The pH of a 0 55 M aqueous solution of hypobromous acid HBrO at 25 C is 4 48 What is the value of K for HBrO Select one O a 2 0 x 10 9 O b 3 3 x 10 5 O c 3 0 x 104 Od 1 1 x 10 CO10 5

11 At 600 K 200 bar a 1 3 molar ratio mixture of A B react to form an equilibrium mixture containing 2 XAB 0 60 Assuming ideal gas behaviour calculate Kp for the reaction A g 3B g 2AB g a 3 33 10 3 c 5 61 x 10 7 b 3 33 10 11 d 9 87 x 10 12

11 Two moles of each reactants A and B are taken in the reaction flask They react in the following manner A g B g C g D g At equilibrium it was found that the concentration of C is triple that of B The equilibrium constant for the reaction is a 4 5 c 9 2 For the reaction b 6 d 1 6