Physical Chemistry Questions

The enthalpy of formation of ammonia is 46 0 k mol The enthalpy change for the reaction 2 NH3 g 2 N2 g 3 H g is a 46 0 k mol 1 b 92 0 kJ mol 1

S rhombic O g SO g AH 297 5 kJ S monoclinic O g SO g AH 300 kJ The above data can predict that 1 Rhombic sulphur is yellow in colour 2 Monoclinic sulphur has metallic lustre 3 Monoclinic sulphur is more stable 4 AH Transition process of S R to S M is endothermic

Consider the following six electronic configurations remaining inner orbitals are completely filled and mark the incorrect option 3s 3p 3s 1 4s IV 3p II 1 3d 4s 4p GHI V I CH a Stability order II I IV III 3s III T 4s VI 1 3d TIT 3d b Order of spin multiplicity IV III I II c V does not violate all the three rules of electronic configuration d If VI represents A and A when kept near a magnet acts as diamagnetic substance 1 Which of the following set of quantum numbers belong to highest energy

i Cu 2HCl CuCl H g E Cu Cu 0 34 V ii Zn 2IICI ZnCl H E Zn Zn 0 76 V iii Ag HCl AgCl H g 2 E Ag Ag Which of the above reactions is feasible 1 ii 3 iii 0 80 V 2 i 4 All

Question Is the specie paramagnetic Statement 1 The atomic number of specie is 29 The charge on the specie is 1 Statement 2 A Statements 1 alone is sufficient but statement 2 is not sufficient B Statement 2 alone is sufficient but statement 1 is not sufficient C Both statement together are sufficient but neither statement alone is sufficient D Statement 1 2 together are not sufficient

Pro A compound contains 4 07 hydrogen 24 27 carbon and 71 65 chlorine Its molar mass is 98 96 g What are its empirical and molecular formulas

What can be achieved can be prevented a Drinking boiled and filtered water b Avoiding smoking and alcoholism c Regular balanced diet and exercise d Proper checking of blood before blood donation

Naturally occurring thallium consists of two stable isotopes T1203 and T1205 atomic masses 203 0 and 205 0 respectively and has an average atomic mass of 204 4 What is the percentage of T1 205 A 14 0 B 70 C 50 0 D 64 7 Hai l NOL

O an Ecell or A G for cell reaction ever be equal to zero

2 8 15 The potential energy of an electron in the hydrogen atom is 6 8 eV Indicate in which excit state the electron is present a first b second c third d fourth lestron present in N shell of the Be ion 34

4 Solute flows from low concentration to high concentration 1 mole glucose is added to 1 L of water K H O 0 512 K kg mole 1 boiling point of 1 373 512 C 3 99 488 C 2 100 512 C 4 372 488 C tion will be nivod If solution has vapour pressure 340 mm Hg

15 Consider a cube containing n unit cells of a cubic system A B a n 16 p Arrangement of atoms A plane ABCD obtained by joining the mid points of the edges on one of its identical faces had atoms arranged as shown Let p be the packing fraction Choose the correct option 22 21 2 11 21 D b n 8 p c n 4 p 14 B T

Given in hydrogenic atom V E K stand for radius potential energy total energy and kinetic energy in nth orbit Find the value of U v x y of column I from column II JEE 2006 Column I A B C U In Vn Kn oc Ex ZY Z Atomic number Orbital angular momentum electron Column II P 1 Q R 2 To

18 Liquids A p 360 mm Hg and B pg 320 mm Hg are mixed If solution has vapour pressure 340 mm mole fraction of B in the solution will be 1 3 33 34 2 34 1 4

2 An atom has x energy level then total number of lines in its spectrum are 1 1 2 3 x 1 2 1 2 3 x 3 1 2 3 x 1 4 x 1 x 2 x 4

derstanding The pKa of HNO2 is 3 37 The pH of HNO2 in its 0 01 mol L 1 aqueous solution will be 1 5 37 2 2 69 3 1 69 4 0 69

4th 5th and 6th period elements can form complex compounds by coordinate covalency due to the presence of vacant d orbitals

Select the correct option s 8 A Specific activity of U235 is greater than specific activity of U O All U is U235 B Activity of 1 mol U235 is greater than activity of 1 mol U O All U is U235 C Decay constant of U235 is same whether it is pure U235 or U O All U is U235 D Rate of radioactive disintegration increases with increase in temperature 3 8

25ml 0 2M Ca OH is neutralised by 10ml of 1M HCl Then pH of resulting solution is 1 1 37 3 12 2 9 4 7

12 An ideal gas is taken through the cycle 19 Heat capacity Cy of an ideal gas is X K mole K To rise its temperature from298 K to 318 K heat to be supplied per 10g gas will be B C A as shown in figure If net A heat supplied to the gas in the VA in KJ MW 16 cycle is5J the 1 16X work done by the 3 32 X gas in the process 1 27K Cal 3 33K Cal C N 5 JE 15 For an ideal gas av 2 10J E H and heat capacities AH 13 Latent heat of vapourisation of a liquid at 500 K and latm pressure is 10K Cal mole What is the change is internal energy when 3 mole n liquid vapourised at the same temperature 7 HINT AHAE AnRT 2 7K Cal 4 25K Cal 202 3 15J 11 10 P N m 4 20J 14 The molar heat capacity of water at constant pressure C is 75 JK mol When 1 OKJ of heat is supplied to 100g of water which is free to expand the increase in temperature of water is 1 1 2K 2 2 4K 3 4 8K 4 6 6K is 22 Which one of the following is not a state function DAH 2 AS 3 S 4 W 23 A gas absorbs 250 J of heat and expands from 1 litre EDUCATION Me to 10 litre at constant temperature against 1 zero 4 AH 16 For a gas having molar mass M specific heat at constant pressure can be given as M 1 YR M Y 1 17 Molar heat capacity of water in equilibrium Y 3 RM R Y 1 with the ice at constant pressure is 4 YRM Y I 1 Zero 3 40 45 KJK mol 18 Heat capacity of water is 18 cal degree mol The quantity of heat needed to rise tempera ture of 18g water by 0 2 C is X cal Then amount of CH4 to be burnt to produce X cal heat is 2 Infinity 0 4 5 48 JK mol 2 6 25X an 12 20 Change in enthalpy when 11 2 dm of He at NTP is heated in a cylinder to 100 C is assume ideal behaviour Hint AH nCAT for mono atomic gas Cp 5 2R 1 623 5J 3 1227J CH 20 CO 2H O AH 200K Cal 1 1 8 x 10 mol 2 3 6 x 105 mol 3 0 0288 g 4 0 288 mg 21 In which of the following conditions increase in internal energy AE 0 is maximum 7 1 q 500J W 200J 2 q 400J W 200 4 q 400J W 1001 3 q 500J W 200J 2 1039 25J 4 520J external pressure of 0 5 atm The values of q w and AE will be respectively 1 250J 455J and 710J 2 250J 455J and 205J 3 2501 455J and 205J 4 250J 455J and 205J Heat of formation and combustion 24 Heat of combustion of C H is 337 K Cal If 5 6 lit O is used at STP in the combustion heat liberated is K Cal 1 28 08 3 42 06 1 650g 3 327g 2 14 04 4 56 16 25 Human body requires 2370 K Cal of energy daily The heat of combustion of glucose is 790 K cal mole The amount of glucose required for daily consumption is 2 540 4 490 5

Which of the followng process is an example of homogeneous catalysis 1 Haber s process 2 Deacon s process 3 Lead chamber process 4 Bosch process

f Explain emulsions and their types ultiple choice questions The change of liquid to gas is a Freezing b Sublimation c Fusion d Vapori

5 One of the characteristic properties of non metals is that they a are reducing agents b form basic oxides c form cations by electron gain d are electronegative 1993 more polar

2 CH C CH A B a 1 1 H In compounds A and B inductive effect of phenyl group is b 1 1 c 1 1 d 1 1

A sample of steel weighing 0 30 g was subjected to a chemical reaction to convert its sulphur impurity to H S g The evolved gas required 2 40 ml 0 02 N iodine solution Which of the following statement s is are true A B C A lodine is reduced to iodide B H S is oxidized to S C Steel contain 0 256 of S by weight D The reaction of H S with I is a precipitation reaction rather than a redox reaction

O Calculate the solubility of AgCN in 0 4 M KCN solution forryt hounoibai bian salt 104 33 i neglecting complex formation 1 riiw noitus mol bosimninu org ii considering complex formation Given Ksp of AgCN 8 10 10 K of Ag CN 4 10 8 o votligste mootbrand SOLUBILITY CONSIDERING HYDROLYSIS

25 On addition of one ml solution of 10 Naci to 10 ml gold sol in the presence of 0 25 gm of starch the coagulation is just prevented Starch has the following gold number

Liquid benzene CH burns in oxygen according to 2CH 1 150 g 12CO g 6H O g How many litres of O at STP are needed to complete the combustion of 39 g of liquid benzene 1 74 L 2 11 2 L 3 22 4 L 84 L LA

5 In a reversible reaction K K P 40 K Cal The product will be obtained in less amount on 1 Increasing both pressure temperature 2 Decreasing both pressure temperature 3 Decreasing pressure increasing temperature 4 Increasing pressure decreasing temperature

The conductivity of a solution which is 0 1 M in Ba NO3 2 and 0 2 M in AgNO3 is 5 3 Sm If Ag 6 x 10 3 Sm mol 1 Ba 13 x 10 3 Sm mol determine NO in same unit Report your answer after multiplying by 1000

30 The volume of O liberated from 0 96 g of H O at STP is 1 224 6 mL 3 390 0 mL 2 316 2 mL 4 112 5 mL

The Kp of Ag2 CrO4 AgCl AgBr and Agli a respectively 1 1 x 10 12 1 8 x 10 10 5 0 x10 12 8 3 x 10 17 Which one of the following salts w will precipitate last if AgNO3 solution is added to the solution containing equal moles of NaCl NaBr Nal and Na CrO4 1 AgCl 3 Ag CrO4 2 AgBr 4 Agl

Ex One mole of ammonium carbamate dissociate as shown below at 500 K NH COONH s 2NH g CO g If the pressure exerted by the released gases is 6 0 atm the value of Kp is A 7 atm B 3 atm C 32 atm bor D 8 atm

with dilution in case of strong and weak electrolyte 2 HS 2013 3 Define molar conductivity of an electrolytic solution How does molar conductivity vary wit concentration for weak electrolyte 2 HS 2015

6 del of the Atom The set of quantum numbers not applicable to an electron fours are nems 1 1 1 1 3 1 0 0 1 2 1 2 1 0 0 1 1 2 4 2 0 0 1 2

3 Which of the following compound will not show optical isomerism 1 3 X CH CH CH CH 2 CH CH 4 all of these

54 The relation for calculating pH of a weak base is a pH pKw pKb log c 2 1 b pH pKw pKblog c W

positive value of the standard electrode potential o Cu Cu indicates that 201 a this redox couple is a stronger reducing agent than the H H couple b this redox couple is a stronger oxidising agent than H H c Cu can displace H from acid d Cu cannot displace H from acid 115 420

d None of these Calculate the potential of a half cell having reaction Ag S s 2e2Ag s S aq in a solution buffered at pH 3 and which is also saturated with 0 1 MH S aq Given Ksp Ag 25 10 49 K K 10 2 Ka a 1 18 b 0 19 The conductivity of 01 N NaOH solution 0 00 c 0 19 V 1 un d none of these

3 Equivalent conductances of Ba and Cl ions are 127 and 76 ohm cm eq respectively Equivalent conductance of BaCl at infinite dilution is a 139 5 c 203 b 101 5 d 279 2000

4 3 g of a saturated hydrocarbon CnH n 2 is burnt completely and all CO2 were absorbed in aqueous NaOH solution A 300 mL 2M NaOH solution was required A CnH2n 2 O2 COz H2O NaOH CO2 Na2CO3 H O Hence value of n is

Which one of the following electrolytes will be most effective in coagulation of arsenoussulphide As2S3 sol a KCI b NaCl d AICI 3 c MgCl

The pressure exerted by 12g of an ideal gas at temperature C in a vessel of volume V lit is one atm When the temperature is increased by 10 degree at the same volume t pressure increases by 10 Calculate the temperature t and volume V Molecular weight the gas 120 IIT 199

Which of the following salt solution will act as a buffer squi 1 CH COONH aq 2 NH Cl aq 3 CH COONa aq 4 NaCl ac

in the mixture of NaHCO3 and Na CO 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 NaHCO is D y x B y A 2x X N

H H K4 The Qvalue is 4 0 MeV and so this nuclear reaction liberates about 1 MeV per nucleon roughly the same as the fission reaction This reaction can be performed in the laboratory by accelerating a beam of deuterons on to a deuterium target In order to observe the reaction we must get the incident and target deuterons clased enough that the nuclear force can produce the reaction that is we must overcome the mutual Coulomb repulsion of the two particles We can estimate this Coulomb repulsion by calculating the electrostatic repulsion of two deuterons when they are just touching The radius of a deuteron is about 1 5 fm and the electrostatic potential energy of the two charges separated by about 3 fm is about 0 5 MeV We can produce such a beam of deuterons in many of the accelerators available in nuclear physics laboratories The beam currents of such accelerators are typically of the order of microamperes If every particle in the beam produced a reaction hardly a reasonable assumption the total power produced would be 4W An output of 4W assuming we could extract every bit of the energy liberated in the reaction which appears as the kinetic energies of the products H and H hardly makes this device a useful power source According to the passage the fusion reaction initiated by accelerators in laboratories is not useful source of energy because A Q value per reaction is very low C Radioactive daughter nuclei are produced B The energy losses are high D The power output is low For initiating the reaction the energy of incident deuterons should be of the order of B 1 0 MeV A 0 5 MeV C 4 0 MeV D 4 5 MeV What is the mass of tritium atom if mass of hydrogen atom 1 0078 amu Mass of Deuterium atom 2 0141 amu 931 5 MeV c A 3 0161 amu B 3 0204 amu C 3 0247 amu D 3 0118 amu

576 Mixture of acetone and methyl alcohol car separated by 1 Simple distillation 2 Fractional distillation 3 Sublimation

Bond enthalpies of H X and HX are in the ratio 2 12 If enthalpy of formation of HX is 50 kJ mol the bond enthalpy of X is a 100 kJ mol c 200 kJ mol 1 b 300 kJ mol d 400 kJ mol

Which of the following is incorrect about galvanic cell 1 Oxidation occurs at anode 2 reduction occurs at cathode 3 the electrode at which electrons are gained is called cathode 4 the electrode at which electrons are lost is called cathode

hydrolysis of the salt should be a 5 b 10 c 20 of these 77 What is the hydronium ion concentration of a 0 02 M solution of Cu2 solution of copper perchlorate The acidity constant of the following reaction is 5 10 Cu2 aq 2H O l Cu OH aq H O aq b 7x10 4 c 5x 10 4 a 1x 10 5 d 1x 10 4 for the following reaction given that the hydronium