Physical Chemistry Questions

Two liquids A and B form an ideal solution The solution has a vapor pressure of 700 torr at 80 C It is distilled till 2 3rd of the solution is collected as condensate The composition of the condensate is x A 0 75 and that of the residue is x 0 30 If the vapor pressure of the residue at 80 C is 600 Torr which of the following is are true A The composition of the original liquid was x 0 6 B The composition of the original liquid was x 2500 C PO 3 D P 500 Torr Torr 0 4

In qualitative analysis the metals of Group I can be separated from other ions by precipitating them as chloride salts A solution initially contains Ag and Pb2 at a concentration of 0 10 M Aqueous HCI is added to this solution until the Cl concentration is 0 10 M What will the concentrations of Ag and Pb be at equilibrium Ksp for AgCl 1 8 x 10 10 Ksp for PbCl 1 7 x 10 5 1 Ag 1 8 x 10 11 M Pb 1 7 x 104 M 2 Ag 1 8 x 10 7 M Pb 1 7 x 10 6 M 3 Ag 1 8 x 10 11 M Pb2 8 5 x 10 5 M 4 Ag 1 8 x 10 9 M Pb 1 7 x 10 M

3 a b c and a p 7 90 a b c and a p 90 and y 120 When a 20 mL of 0 08 M weak base BOH is titrated with 0 08 HCL the pH of the solution at the end point is 5 What will be the pOH if 10 mL of 0 04 M NaOH is added to the resulting solution Giver log 2 0 30 and log 3 0 48 1 5 40 2 4 92 3 None of these 4 5 88

Consider the electrochemical cell Zn Zn Ag Ag 0 01 M 1L 0 1 M 1L EAg Ag 0 8 V E2n 2 0 77 V If x L of H O is added in anodic chamber and y L of H O is added in cathodic chamber such that emf of cell is more than E at 298 K The possible value of x and y are A 9010 B 254 C 315 D 133

4 A solution of 500 ml of 0 2 M KOH and 500 ml of 0 2 M HCl is mixed and stirred the rise in temperature is T The experiment is repeated using 250 ml of each solution the temperature raised is T Which of the following is true a T T c T 4T b T 2T d T 9T

a b c d List I Cyanide process Floatation process Electrolytic reduction Zone refining List II 1 Ultrapure Ge 2 Pine oil 3 Extraction of Al 4 Extraction of Au 1 a 3 b 1 c 4 d 2 2 a 4 b 2 c 3 d 1 3 a 3 b 2 c 4 d 1

An aqueous solution containing 0 01 M Fe CIO4 3 0 01 M Fe CIO4 2 and 0 01 M HCIO was titrated with a concentrated solution of NaOH at 30 C so that changes in volumes were negligible Calculate the redox potential of Fe Fe2 electrode at pH values 2 2 4 2 6 0 8 2 and 10 assuming that new species formed during titration were Fe OH 3 and Fe OH 2 only Given Ksp of Fe OH 3 10 37 1 Fe3 Fe2 0 77 V Ksp of Fe OH 10 18 4

87 A new electron enters the orbital when 1 n m is maximum 2 n I is minimum 3 n I is maximum 4 n 1 is maximum 88 0 5 mol of Al2 SO4 3 contains 1 0 6 mol of oxygen atom 2 6 mol of oxygen atom 3 3 6 mol of oxygen atom 4 12 mol of oxygen atom

2 3 1 g of dry green algae absorbs 4 7 x 103 mole of CO per hour by photosynthesis If the fixed carbon atoms were all stored after photosynthesis as starch C6H 0 05 how long would it take for the algae to double their own 7 88 hours weight assuming photosynthesis takes place at a constant rate

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

A graph is plotted between Ecell and log Zn Cu linear with intercept on Eell axis equals to 1 10 V Calculate Ecell for the cell 2 Zn s Zn 0 1 M Cu 0 01 M Cu The curve is

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

In CCP there are 8 tetrahedral sites and all are present completely inside the unit cell There are 13 octahedral sites out of which 1 is at the body centre and 12 are at edge centres Like CCP another packing is HCP in which the number of tetrahedral sites that are completely inside one unit cell is x Mark the value of x Assume those sites are completely inside the cell that are not shared between unit cells Answer 00 01 02 03 04 05 06 07

H C H Br A H CH3 Which of the following statement is true 1 A is formed by anti addition and is meso 2 A is formed by syn addition and is meso 3 A is formed by anti addition and is racemic 4 A is formed by syn addition and is racemic

Ex 31 An organic compound A contains 40 carbon 6 7 hydrogen and rest oxygen Its vapour density is 15 On reacting with a concentrated solution of KOH it gives two compounds B and C When B is oxidised the original compound A is obtained When C is treated with concentrated HCl it gives a compound D which reduces Fehling s solution as well as ammoniacal AgNO3 solution and also gives effervescence with NaHCO3 solution Write the structures of A B C and D

3 CuS and ZnS 4 C If two molecules of A and B having mass 100 amu and 64 amu respectively and rate of diffusion of A 12x10 then what will be the rate of diffusion of B 1 15x10 2 64x10 3 5x10 and NIS 4 46x10

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

8 An organic compound compound contains carbon hydrogen and oxygen Its elemental analysis gave C 40 H 6 67 and O 53 33 The empirical formula of the compound is 1 CH3O 2 C H4O 3 CH2O 4 CH4O 9 12 044 x 1022 molecules of glucose are present in 500 mL of its solution The molarity of the solution is 1 0 01 M 3 0 01 M 2 0 4 M 1 02 M

Consider these generic half reactions Half reaction X aq eX s y aq 2e Y s Z aq 3e Z s 1 Identify the strongest oxidizing agent Ox Oz Oz OY Ox OY E V 1 49 0 70 1 22 Identify the weakest oxidizing agent Oz Ox OY OY Ox Oz

41 20 g Ar gas is allowed to expand reversibly and isothermally at 300 K from 5 L to 10 L Calculate the approximate value of work done Take R 25 3 J K mole at wt of Ar 40 u a 862 5 J b 375 J c 1437 5 J d 1250 J

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

Given NO30 NO acidic medium HD E 0 8 V NO3 NH OH acidic medium E 0 74 V At what pH the above two half reactions will have same EMF values Assume the concentration of all the species to be unity Take 0 059 0 06

66 If 10 g of H2 reacts with 42 g of N2 then identify the correct statement 1 1 mol of H is left in excess 2 N is the limiting reagent 3 2 5 mol of NH3 is formed 4 0 5 mol of N is left in excess 67 Which of the following pairs of species are isodiapheres 1 H and D 3 30 Si 4 and 1P15 2 15N and 708 4 40 A18 and 40K19

25 The molar conductivity of HCl NaOH and CH3COONa are 425 188 96 S cm2 mol lat 298 K The molar conductivity of CH3COOH at the same temperature is Scm mol a 333 c 325 b 451 d 550 01 M weak acid is

a 23 A saturated solution of Ca RCOO contains 0 6 mole in 2 litre solution pOH of the solution is 5 60 If 90 dissociation of the salt takes place then what is the pK of the carboxylic acid a 2 8 log 0 54 b 2 8 log 0 54 c 2 8 log 0 27 d None of these

temperature and low pressure 1 The value of AG for the phosphorylation of glucose in glycolysis is 13 8 kJ mol What would be the value of K at 298 K for the above process a e 55 69 b e 5 569 C e 0 5569 d e 556 9

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

5 The equivalent conductivity of 0 1 M weak acid is 100 times less than that at infinite dilution The degree of dissociation of weak electrolyte at 0 1 M is a 100 c 0 01 b 10 d 0 001 tivities of a uni univa

When 100 mL of 1 0 M HCl is added to a 2 0 g piece of CaCO3 CO2 is produced at a certain rate Which of the changes below will NOT increase the rate of this reaction a b Adding 100 mL of 2 0 M HCl in place of 100 mL of 1 0 M HCl Heating the 100 mL of 1 0 M HCl before adding it to the CaCO3 c Adding 100 mL of 1 0 M HCl to 2 0 g of powdered CaCO3 d Adding 150 mL of 1 0 M HCl in place of 100 mL of 1 0 M HCI

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

Expansion of ideal gas takes place from 10 L in vacuum isothermally at 300 K Which of the following is correct 1 H 0 3 w 0 2 q 0 famonin Vaccino All of these a Pusa Road New Delhi 110005 Ph 011 47623456 AH W

1 2 40 of a mixture of 0 2 moles of N 0 6 moles of H react to give NH according to the equation N g 3H g 2NH g at constant T P Then ratio of final volume to initial volume of gases is a 4 5 c 7 10 b 5 4 d 8 5

34 Select the correct statement a If H y 10x then pH x log y X 1 10 then pH x log y c pH of a solution 14 log OH d All of the above b If H y

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

possible values of n l and m for this electron Question Type Single Correct Type 1 n 3 l 0 m 0 2 n 3 l 1 m 1 0 1 3 n 3 l 2 m 2 1 0 1 2 4 n 3 l 3 m 3 2 1 0 1 2 3 ne

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

In the following sequence of reactions the maximum number of atoms present in one plane o molecule C is Red hot A CH CI 1 eq Anhydrous AICI C Cu tube A is a lowest molecular weight alkyne B

27 According to the diagram given below the value of AH for conversion of A to B is a 40 c 120 Heat of Reaction 120 80 40 A B Reaction Course b 40 d 120 3

53 Two elements A and B combine to form two compounds A B and A2B5 If 0 2 mol of A B weighs 8 8 g and 0 1 mol of A2B5 weighs 10 8 g then atomic weight of A and B respectively are 1 16 u 12 u 2 12 u 16 u 3 14 u 16 u 4 16 u 14 u 54 If vapour density of a triatomic gas X3 is 150 then atomic mass of X is 1 60 u 3 100 u 2 90 u 4 120 u

In the Cannizzaro reaction given below 2Ph CHO Ph CH OH PhCOO in the presence of OH the slowest step is 1 The attack of OH at the carbonyl group 2 The transfer of hydride to the carbonyl group 3 The abstraction of proton form the carboxylic group 4 The deprotonation of pH CH OH

a 35 The P T graph as given below was observed for process on an ideal gas Which of the following statement is true P A a W ve AH ve b W ve AH ve c W ve AH ve d W ve AH ve T B

9 For the reaction N 0 g 2NO g the equilibrium constant is K The equilibrium constant is K for the reaction 2NO g O g 2NO g What is K for the reaction NO g N g O g K K 1 4K K b 1 2K K K K

1 For a given mixture of NaHCO3 and Na2CO3 volume of a given HCl required is x ml with phenolphthalein indicator and further y ml required with methyl orange indicator Hence volume of HCl for complete reaction of original NaHCO3 is a 2x b c y X 2 d y x

pressure of H S g decreases at given temperature d All option are correct 19 200 mL of M 5 dibasic acid is mixed with 150 mL of M 2 monoacid base The pH of the resulting solution is likely to be a More than 7 c Equal to 7 b Less than 7 d Uncertain

36 X gm of ethanal was subjected to combustion in a bomb calorimeter and the heat produced is Y Joules Then a AE XJ b AE YJ combustion combustion combustion combustion C AE d AH 7 Enthalny 44Y X J mol 1 44Y X J mol

2 2 dichloro propane on hydrolysis yields 1 Acetone 2 2 2 Propane diol 3 Isopropyl alcohol 4 Acetaldehyde E of Fe Fe 0 44V E of Cu Cu 0 34 V Then in the cell 1 Cu Oxidizes Fe 2 Fe Oxidizes Cu 3 Cu Reduces Fe 4 FeReduces Cu