Physical Chemistry Questions

Equal volume of 0 2 N Na2SO4 and 0 1 N BaCl2 solutions are mixed together Assume that BaSO4 is completely insoluble If K H O 0 52 K kg mol what would be the normal boiling point of the resulting solution Assume molality molarity 100 15 C 100 75 C 100 091 C 100 175 C

9 For real gases van der Waals equation is an V2 where a and b are van der Waals constants Two sets of gases are I 0 CO H and He CH4 O and H II The gases given in set I in increasing order of b and gases given in set II in decreasing order of a are arranged below Select the correct order from the following written as P V nb n RT a I He H CO O II CH4 H O b 1 O He H CO II H O CH4 c 1 H He O CO II CH4 O H d 1 H O He CO II O CH4 H Mains 2012 10 Equal volumes of two monatomic gases A ad ssure

Consider that the multistep reaction that has the overall reaction 2A 2B C D is obtained by the following mechanism A B I 21 B C X X A D What is the overall order of the reaction 09 05 fast slow fast 012

66 One of the hazards of nuclear explosion is the generation of Sr90 and Subsequent incorporation in bones This nucleide has half life of 28 1 Suppose one microgram was absorbed by a new born child how much Sr remain in his bones after 20 yr 1995 2M

M a 40 If degree of dissociation is 0 01 of decimolar solution of weak acid HA then pK of acid is a 2 b 3 Jes 5 d 7 41 What concentration of HCOO is present in 1 8 x 107 a solution of 0 01 M HCOOH Ka

Calculate the enthalpy change on fusion of 1 mol of ice at 5 C to water at 5 C Given AH 6 03 kJ mol at 0 C Cp H O 0 75 3J mol K Cp H O s 36 8 Jmol K 1 6 59 kJ mol 6 59 kJ mol 3 ALLI 3 29 kl mol

4 they The cations having same size and charge one having n 1 d ns configuration possess more polarising power because is 1 It is d bolock element 3 It has effective shielding of d electrons 2 It has inert gas configuration 4 it has more Zeff due to poor shielding of d electrons MOLECULAR STRUCTURE

The specific rotation of enantiomer A is 87 3 A mixture of enantiomer A and A the enantiomer of A is subjected to polarimetry and an observed rotation of 34 2 is obtained what is the EE for this mixture 39 2 A 60 8 A 39 2 A

ow is 2nd statement true 3 pr 9 Function of salt bridge is are a It completes the cell circuit b It allows the movement of ions from one solution to other without mixing of the two solutions c It maintains the electrical neutrality of the solution in two half cells NCERT Pg 66 1 a b 3 Only a 2 a b c 4 b c

If the density of ethanol is 0 78 kg L then volume of ethanol he making 2 L of 0 5 M solution is Options 45 2 mL 58 97 mL 71 4 mL 25 5 mL Solution Answer 2 NCERT Reference Some basic concepts of chemistry XI Part 1 Page No 26

Given O2 g 20 g NO g O3 g NO2 g O2 g 302 g 203 g What is the standard reaction enthalpy for the following reaction NO g O g NO2 g O 355 kJ mol O 555 kJ mol 306 kJ mol 592 kJ mol 306 5 kJ mol AH 498 4 kJ mol AH 200 0 kJ mol AH 285 4 kJ mol

37 A 0 10 M solution of HF is 8 0 dissociated What is the K a 6 4 x 10 4 b 8 8 x 10 4 c 6 95 x 10 d 7 6 x 10 38 A weak base MOH of 0 1 N concentration shows a pH value of 9 What is the p

61 The following equilibrium are given N 3H 2NH3 K N 0 K H 1 1 20 2 H O K The equilibrium constant of the reaction 2NO 3H O in terms 2NH3 5 2 0 of K K and K is K K A K 2NO B 2 K K K C K K3 K D K K K 1 1

Number of atoms in 0 2 g molecule Br308 is molar mass of Br308 is 368 g mol 0 22 NA 2 2 NA 0 2 NA 0 2 368 Read More x11NA only one is correct

During electrolysis of aq NaCl using Pt electrodes variable source 20 current is used where t Current is passed for 965 second 965 then select the correct statement s Take 1 F 96500 C mol Number of moles of H gas evolved is 0 05 Number of moles of O gas evolved is 0 025 Number of moles of Cl gas evolved is 0 05 Number of moles of Cl gas evolved is 0 025

During electrolysis of aq CH COONa solution current of 965 A is passed for 10 second using Pt electrodes select the correct statement s Take 1 F 96500 C mol 01 12 L of H gas at STP is evolved at cathode C He gas evolved at anode If the hydrocarbon gas evolved at anode is burnt with excess of O the moles of CO gas evolved is 0 2 During electrolysis total moles of gases evolved in 0 2

In fcc arrangement the distance between adjacent layers of close packing is 81 65 pm then the smallest possible radius of a foreign atom that can be placed in a void is 50 00 pm

2 The wavelength of photon obtained by electron transition between two levels in H atom and singly ionised He are and respectively then 1 2 2 3 2 2 2 4 2 4

2FAF5 AF3 For the above change which statement is correct 1 Central atom A belongs to 15th group 2 In each step two coordinate bonds are formed 2F AF7 III 3 Central atom A has five electron in p subshell of its valence she 4 No such change is possible

The low boiling azeotrope is a mixture of two miscible liquids that when boiled produce the same composition in the vapor phase a is a vertical line form the vapor phase to the liquid phase O b OC is a mixture of two miscible liquids that when boiled produce the different composition in the vapor phase O d 1s is a mixture of two immiscible liquids that when heated becomes completely miscible

What should be the momentum in gram centimetre per second of a particle if its de Broglie wavelength is 1 and the value of h is 6 6252 x 10 27 erg second 1 6 6252 x 10 19 gcm s 2 6 6252 x 10 21 gcm s 3 6 6252 x 10 24 gcm s 4 6 6252 x 10 27 gcm s

A graph is plotted between the vapour pressure and mole fraction of a solution containing benzene and toluene Choose the correct options 80 Liquid L Pressure mmHg 60 40 20 0 0 0 2 L V b Vapour V 0 4 0 6 0 8 1 0 X benzene a At the point a the mole fraction of toluene is 0 80 b b c represents condensation c c d represents vapourization YO d c d represents vapourization as well as condensation

7 An ideal gas can t be liquefied because a its critical temperature is always above 0 b its molecules are relatively smaller in size c it solidifies before becoming a liquid d forces operative between its molecules are negligible 1992

In the electrolysis of KI I is formed at the anode by the reaction 2 1 2e After the passage of current of 0 5 ampere for 9650 seconds I formed required 40 ml of 0 2 M Na S O3 5H O solution in the reaction 12 25 03 What is the percentage current efficiency 16 48 32 21

2 3 moles of a certain gas are confined in a cylinder Calculate the expansion work when the gas expands isothermally and reversibly from an initial vol of 0 5L to a final volume of 2 5L at 30 C O a 92 03 kJ O b 92 03 kJ Oc 9 3kJ O d 3 7 kJ

If the standard enthalpy of combustion of solid phenol is 3054 kJ mol at 298 K and its standard molar entropy is 144 0 JK 1 mol 1 then the standard Gibbs energy of combustion of phenol is O a A Go 3084 kJ mol Ob A GO Oc A G Od4cG 3077 kJ mol 1 3074 kJ mol 3097 kJ mol 1

Assuming the vapour pressure of water is increased from 30 to 31 mm Hg at 25 C against an external pressure of 10 atm If the vapour pressure is to be maintained at 30 mm Hg for 1 L of water 55 5 moles at 25 C and 10 atm pressure how much NaCl in moles is to be added to the water 0 765

13 10 Suppose you need to know the number of moles of a gas from measurements of its pressure temperature and volume We assume that the gas is ideal a possible source of systematic error Perhaps our measurements of P V and T are P 0 268 0 012 atm V 1 26 0 05 L T 294 2 0 3 K R 0 082058 L atm K mol Report the number of moles of gas with uncertainty Use the calculus based approach

ic species 5 Which is incorrect statement 1 N has greater dissociation energy than N 2 O has lower dissociation energy than 0 O 3 Bond length in N is less than N 4 Bond length in NO is less than in NO

d P is the pressure of the gas when only one mole of gas is present Pure hydrogen sulphide is stored in a tank of 100 litre capacity at 20 C and 2 atm pressure The mass of the gas will be a 34 g b 340 g c 282 68 g d 28 24 g A weather balloon filled with hydrogen at 1 atm and 27 C has volume equal to 12000 litres On

Calculate the heat produced in kJ when 224 gm of CaO is completely converted to CaCO3 by reaction with CO at 27 C in a container of fixed volume Given AH CaCO3 s 1207 kJ mol AH CaO s 635 kJ mol AH CO g 394 kJ mol Use R 8 3 J K mol 85 702 04 kJ 2 721 96 kJ 3 712 kJ

The decomposition of a certain mass of CaCO3 gave 11 2 dm of CO gas at STP The mass of KOH required to complete neutralise the gas is 1 28 g 2 56 g 3 14g 4 1 2 g The Vividh Bharti Station of All Indian Radio

Equal volume of 0 2 N Na SO4 and 0 1 N BaCl solutions are mixed together Assume that BaSO4 is completely insoluble If Ku H O 0 52 K kg mol what would be the normal boiling point of the resulting solution Assume molality molarity O 100 15 C O100 75 C 100 091 C 100 175 C

During electrolysis of H SO4 aq with high charge density Marshall s acid formed as a by product In such electrolysis 22 4 L H g and 5 6 L O g liberated at STP at electrode The number of moles of Marshall s acid formed is x the value of x is 1 0 25 2 0 5

35 Four lowest energy levels of H atom are shown in the figure The number of emission lines could be 1 3 2 4 3 5 4 6 4 432 95 n 1 In the above problem the number of absorption lines could be t 1 3 2 4 3 5 4 6

16 The energy absorbed by each molecule A 23 The of a substance is 4 4 x 10 19 J and bond energy per molecule is 4 0 10 19 J The kinetic energy of the molecule per atom will be a 2 2 10 9 J c 4 0 10 20 J b 2 0 10 9 J d 2 0 10 20 J 2009 7 If a gas expands at constant temperature it per r a c 24 At w N w at 50

When equal volumes of methanol CH3OH and water are mixed the temperature increases a What does this observation tell you about the value of H of mixing b Let s assume that hydrogen bonding is the only energetically significant non covalent interaction in both the pure liquids and in the mixture Based on your answer in part a will the total number of hydrogen bonds in the mixture be higher or lower than in the separate liquids Explain c If we have infinite time to observe the mixture will we ever see it revert to the

A monatomic ideal gas is the working substance for a refrigerator that undergoes the cyclic process ABCDA shown in the PV diagram The processes are all isochoric or isobaric with pressures between P and 2P and volumes between V and 2V What is the coefficient of performance for this refrigerator P 2P Po

37 At 727 C N g 3H g 2NH g AH 123 77 N NH 3 5R 4R Substance H 3 5R C The heat of formation of ammonia at in kJ mol at 270 a 44 42 b 44 42 c 88 85 d 88 85 a a C 45 C

5 What is the correct representation of reaction occurring when HCI is heated with MnO 1 MnO4 5CI 8H 2 MnO 2Cl 4H 3 2MnO 4Cl 8H 4 MnO 4HCI Mn2 5Cl 5H 0 Mn2 Cl 2H O 2Mn 2Cl 4H O MnCl4 Cl H O

c AG 0 AS 0 d AG 0 AS 0 52 The enthalpy of formation of ammonia is 46 0 kJ mol The enthalpy for the reaction 2N g 6H g 4 NH3 g is equal to a 46 0 kJ b 46 0 kJ c 184 0 kJ d 184 0 kJ

gives the energy of the electron in orbital d Both a b 39 Consider the following sets of quantum number 1 0 ii iii iv v n 3 2 4 1 3 2 3 0 2 m 0 1 2 1 3 S 1 2 1 2 1 2 1 2 1 2 Which of the following sets of quantum number is not possible a i ii iii and iv b ii iv and v c i and iii d ii iii and iv

33 When is deviation more in the behaviour of a gas from the ideal gas equation PV nRT a At high temperature and low pressure b At low temperature and high pressure c At high temperature and high pressure d At low temperature and low pressure 1993 A closed flack contains water in all its three

60 Al O is reduced by electrolysis at low potential and high current If 4 0 x 104 amperes of current is passed through molten Al O for 6 hours what mass of aluminium is produced Assume 100 current efficiency At mass of Al 27g mol A 1 3 x 104 g C 8 1 x 104 g B 9 0 x 10 g D 2 4 x 105 g

a mixture that possesses chiral center s and is optically active a mixture that possesses chiral center s but is optically inactive None of the above a pure compound that possesses chiral center s but is optically inactive

What is the change in chemical potential of a perfect gas when its pressure is increased isothermally from 92 0 kPa to 252 0 kPa at 50 C 2 71 kJ mol a b c d 4 5 kJ mol 3 1 kJ mol 71 kJ mol

ecre CI O S O OPCI O P O 4 g oxygen expand at STP to its original volume Then work don 1 260 cal 2 180 cal 3 130 cal 4 272 8 cal 7 Which of the following is displaced by Fe 2 Zn 4 All of these Which of the following will not give ether as product 1 Ag 3 Na 68 CH CH I CU ZONS CH 00 ONa JONa CH CH CH So

Name the substance oxidized and redu ced and also identify the oxidizing agen ts and reducing agents in the following reaction 1 Fe203 3Co 2Fe 3Co2 2 3MnO2 4AI 3Mn 2Al203 3 H2S SO2 S H2O

1 Pro Madical 2021 TT 4 19 08 2021 2 For an elementary reaction A 2B C the initial pressure of A and B are 0 5 and 1 0 atm respectively if after time t the pressure of A becomes 0 2 atm what is the ratio of rate I G 1 16 250 2 25 16 5 3 16 16 4 5

Column I contains different lattice types and column II different operations and properties of lattice Match the column I with column II Column I Q1 NaCl type lattice Q2 CsCl type lattice Q3 Na O type lattice Q4 CaF2 type lattice Column II A1 If all the ions along one of the C 4 axis are removed then the formula of lattice will be AB A2 If all the ions along one of the C 4 axis are removed then the lattice will lose all the cations A3 a 2 3 r r A4 Coordination number of at least one ion is 4 A5 If all the ions along one of the C 4 axis are removed then the lattice will become positively