Physical Chemistry Questions

5 4 A solution at 20 C is composed of 1 5 mol of benzene and 3 5 mol of toluene If the vapour pressure of pure benzene and pure toluene at this temperature are 74 7 torr and 22 3 torr respectively then the total vapour pressure of the solution and the benzene mole fraction in equilibrium with it will be respectively 1 35 0 torr and 0 480 2 38 0 torr and 0 589 30 5 torr and 0 389 3 35 8 torr and 0 280 U10 camera

The ionic radii of Rb and I are 1 46 and 2 16 A respectively The most probable type of structure exhibited by it is 1 CsCI type 3 ZnS type 2 NaCl type 4 CaF type

0 Volume of gases evolved when dil H SO4 i electrolysed using 2 F at STP 1 22 4 L 2 11 2 L 3 33 6 L 4 4481

52 Which of the following gaseous molecules is polar a CS2 b BF3 c SnCl d PbC14

4 Which is the incorrect statement 1 Density decrease in case of crystals with Schottky s defect 2 NaCl s is insulator silicon is semiconductor silver conductor quartz is piezo electric crystal 3 Frenkel defect is favoured in those ionic compounds which sizes of cation and anions are almost equal 4 FeO0 98 has non stoichiometric metal deficiency def CT 30171 r

d 0 477 M and 0 477 M 2010 6 10 g of hydrogen and 64 g of oxygen wer filled in a steel vessel and exploded Amour of water produced in this reaction will be a 3 mol b 4 mol c 1 hol d 2 mol 200

The species in which the 1 NO2 2 NO 3 NO The pair in which phosphorous atoms have a formal oxidation state of 3 is 1 Pyrophosphorous 2 Orthophosphorous and pyrophosphoric acids and pyrophosphorous acids 3 Pyrophosphorous and hypophosphoric acids 4 Orthophosphorous and hypophosphoric acids molecular force is most responsible in allowing xenon gas to liquefy N

final solution was found to be 12 with current efficiency 96 5 An aq solution of 1 0 MASO and 1 0 MAGNO is electrolysed at 298 K If concentration of Ag be brought down before A start to deposit in electrolysis is 10 M What is the value of x 0 08 05 VE Given ed in amp for electrolysis of 300 ml aqueous NaCl solution If after 5 minutes pH of Ehm 2 303RT F

54 When 0 02 moles of NaOH are added to a litre of buffer solution its pH changes from 5 75 to 5 80 What is its buffer capacity A 0 4 B 0 05 N 5 5 acetic acid was titrated with N 10 C 0 05 D 2 5 NaOH When 25 50 and 75 of titration is over then

4 A solution labelled 65 0 by weight H SO has a density of 1 43 gm ml at 20 C A concentrated soluton of NH is 20 by weight having d 0 898 gm ml what maximum volume of NH solution can be completely neutralised by 5 ml of a concentrated given H SO solution 1 3 4 C

100 g CH 2O6 aq face fai fare 12 40 to facena 93 C Tech full 1 95 5 g al 2 4 5 g 40 18 torr f for k 1 86 kg mol 3 45 5 g 4 47 8 q

The empirical formula of a non electrolyte is CH O A solution containing 6 g of the compound exerts the same osmotic pressure as that of 0 05 M glucose solution at the same temperature The molecular formula of the compound is a C H O c CsH10Os b C H O d C H O 2010

Karnataka Me b Pt H 1 atm HC1 2M 2 1 d Pt H 1 atm HCl 0 5M 141 Which one of the following has a potential more than zero a Pt H latm HCl 1M 2 1 c Pt H 1 atm HCl 0 1M 2

14 The plot given below shows p T curves where p is the pressure and 7 is the temperature for two solvents X and Y and isomolal solutions of NaCl in these solvents NaCl completely dissociates in both the solvents 1 2 ADID vig inson 0 H 760 Pressure mmHg g Temperature K DOR 1 solvent X 2 solution of NaC in solvent X 3 solvent Y 300 4 solution of NaCl in solvent Y On addition of equal number of moles of a non volatile solute S in equal amount in kg of these solvents the eleva tion of boiling point of solvent X is three times that of solvent Y Solute S is known to undergo dimerization in these degree of dimerization is 0 7 in solvent Y the degree of dimerization in solvent X is

69 Among the following the number of elements showing only one non zero oxidation state is Cl F P Na O Sn Tl N Ti

Number of maximum possible electron s in Zn for which n l 4 is 2 uto 4 2n 1 4 3 8 2 6 4 12 2x16

P 49 2 3 An excited Li 2 ion emitted a photon corresponding to the second line of Balmer series This photon liberated an electron from the stationary atom in ground state Find the velocity of the electron emitted a 3 108 cm s 1 b 3 10 4 cm s c 3 x 10 6 cm s sonite 58 d None of these

pH of 0 1 M NaCN solution is 11 then the percentage hydrolysis is 1 0 1 3 0 01 2 1 4 10

In an experiment addition of 5 0 mL of 0 006 M BaCl to 10 0 mL of arsenic sulphite sol just causes the complete coagulation in 34 h The following value of the effective ion is

The amount of NH SO in g which must be added to 500 ml of 0 2 M NH to yield a solution of pH 9 35 K for NH 1 78 x 10 A 5 248 g B 4 625 gm C 5 821 gm D 3 756 gm

Gaseous N O4 dissociates into gaseous NO according to the reaction N O4 8 2NO g At 300 K and 1 atm pressure the degree of dissociation of N O4 is 0 2 If one mole of N O4 gas is contained in a vessel then the density of the equilibrium mixture is 1 1 56 g L ed 2 3 11 g L 3 4 56 g L 4 6 22 g L

3 minimum 4 maximum The strongest covalent bond is formed by the overlap of If considering for same shell 2 sand s orbitals 3 p and dorbitals 1 s and p orbitals In a triplo ho 4 p and p collateral ort

7 5 5 g of a mixture of FeSO4 7H O ar Fe2 SO4 3 9H 0 required 5 4 mL of 0 1N KMnC solution for complete oxidation Calculate mole hydrated ferric sulphate in mixture IIT 198 3 0 5 g sample containing Mp in

5 Which of the following has covalent as well as ioni bond a NaCl b NaOH c H O d HC1

Two solutions of a substance non electrolyte are mixed in the following manner 480 ml of 1 5M of first solution with 520 ml of 1 2M of second solution The molarity of final solution is AIEEE 2005 a 1 20M c 1344M b 1 50M d 2 70M

HOT 29 At equilibrium 500mL vessel contains 1 5 M of each A B C D If 0 5M of C and D expelled out than what would be the K 41 1 2 1 9 3 4 9 4 5 9

8 In which case is the number of molecules of water maximum a 0 00224 L of water vapours at 1 atm and 273 b 0 18 g of water c 18 mL of water d 103 mol of water

3 17 g of a substance was deposited by the flow of 0 1 mole of electrons The equivalent weight of the substance is A 3 17 B 0 317 C 317 D 31 7

Number of unit cells in 0 1 g molecule NaCl is 1 0 1 N 2 0 025 N 3 0 5 N A 4 0 25 N S C V 0

Given the following E values at 25 C Calculate log K for silver bromide AgB sp Ag aq e Ag s E 0 80V E 0 07 V AgBr s e Ag s Br aq Also calculate AG at 25 C for the process AgBr s Ag aq Br aq

36 g H O is electrolysed by passing 3 ampere current What will be time required for complete decomposition in hour 1 17 87 hour 3 35 74 hour 2 15 84 hour 4 25 35 hour

The standard Gibbs energy change at 300 K for the reaction 2A B C is 2494 2J At a given tim 1 1 2 2 the composition of the reaction mixture is A B 2 and C R 8 314 J K mol e 2 718 1 forward direction because Q K 2 reverse direction because Q K 3 forward direction because Q Kc 4 reverse direction because OSK The reaction proceeds in the JEE Main 2015

50 The distance of separation between third and fourth orbit of Li2 is 1 1 23 A 3 2 82 A 2 0 41 A 4 1 41 A

A 6 solution of urea is isotonic with a 0 05 M solution of glucose b 6 solution of glucose c 25 solution of glucose d 1 M solution of glucose 2009

JEE 71 The total number of lone pairs of electrons in melamine is 72 Assuming 2s 2p mixing is NOT operative the paramagnetic species among the following is A Be BY B C C D N JEE 79

Acertain crude oil has an idex of refraction of 1 25 A ship dumps 1 m of this oil into the ocean and it spreads into a thin uniform film on water surface When light of wavelength 500 nm is incident on it the reflected light shows maximum What is the area in km covered by the spilled oil Assume that the thickness of film is minium required to satisfy this criterion

Under the action of force P the constant acceleration of block B is 6 m sec up the incline For the instant when the velocity of B is 3 m sec up the incline Choose the correct option s A Velocity of B relative to A 1m s B Acceleration of B relative to A is 2 m s C The velocity of point C of the cable in ground frame is 4 m s D Velocity of B relative to A is 2m s 20

The freezing point depression constant for water is 1 86 C m If 5 00 g Na SO4 is dissolved in 45 0 g H O the freezing point is changed by 3 82 C Calculate the van t Hoff factor for Na SO4 a 2 63 c 0 381 b 3 11 d 2 05

76 When an excess of a very dilute aqueous solution of KI is added to a very dilute aqueous solution of silver nitrate the colloidal particles of silver iodide are associated with which of the following Helmholtz double layer a Agl Agt r b Agl K NO 3 c AgI NO Agt d Agl I K 3

If valence factor n factor of compound NaHC 0 2H C 0 3K C 0 4A1 C O 3FeC 0 in acid base titration is x and redox titration with KMnO is y then value of y x is A 8 4 B 9 C 11 25 D 12 INH1 0 25M What will be monio LI T TT

In a mole of water vapour at STP the volume actually occupied or taken up by the molecules i e Avogadro number the volume of one molecule is a less than 0 1 of 22 4 litres b about 10 of the volume of the container of 22 4 litres c between 10 to 20 of 22 4 litres d between 2 to 5 of 22 4 litres

Find out number of reactions giving optically active diastereomeric pair b a Me CH Et 1 Cl d HC1 CCI SbCl HI CCL e 2 chlorobutane f Racem ic m ixture of 2 butanol 2 methyl butanoic acid c AICI HBr CC1

133 Which of the following thermodynamic conditions at constant pressure and temperature is necessary for the spontaneity of a process live en is oldierstommad a d U TS PV 0 d U TS PV 0 e b d U TS PV 0 d d TS PV 0

Out of following reactions which is a pseudo first order reaction Inversion of cane sugar Decomposition of ammonia on platinum surface Radioactive decay Decomposition of N O5 into NO and

The pressure of H required to make the potential of H electrode zero in pure water at 298 K is a 10 10 atm c 10 14 atm b 104 atm 10 2 atm d NEET I 2016

Which of the following statement is are true about the ionic solids A B C D Bigger ions form the close packed structure Smaller ions occupy either the tetrahedral or the octahedral voids depending upon their size Occupation of all the voids is not necessary The fraction of octahedral or tetrahedr voids occupied depends upon the radii

A unit cell of BaCl fluorite structure is made up of a four Ba ions and four Clions 2 2 b four Ba ions and eight CIT ions 2 c eight Ba ions and four CI ions d four Ba2 ions and six Cl ions

Calculate pH of following solutions 0 1 M HCl a b c d f on 0 1 M CH COOH K 1 8 x 10 5 log 1 8 0 13 0 1 M NH OH K 1 8 10 5 10 8 M HCI 401 20 02 log 1 051 0 03 10 10 M NaOH 10 6 M CH COOH K 1 8 10 5 10 8 M CH COOH K 1 8 x 10 5 401 20 02 log 1 051 0 031 h Decimolar solution of Baryta Ba OH diluted 100 times 10 3 mole of KOH dissolved in 100 L of water i Equal volume of HCl solution PH 4 0 0019 N HCl solution

3 On adding AgNO solution to KI solution a negatively charged colloidal sol will be formed in which of the following conditions AgNO3 Kro Ag I K NO a 100 mL of 0 1 M AgNO3 100 mL of 0 1 M KI b 100 mL of 0 1 M AgNO3 50 mL of 0 2 M KIY c 100 mL of 0 2 M AgNO3 100 mL of 0 1 M KI d 100 mL of 0 1 M AgNO3 100 mL of 0 15 M KI

The following equations of state are occasionally used for approximate calculation on gases b Gas X PV RT 1 V m Gas Y P Vm b RT Assuming that gas X and Y actually obeyed above equation of state respectively then choose the correct statement A Gas X is more liquefiable than Gas Y B Gas X and Y both are liquefiable C Neither Gas X nor Gas Y is liquefiable D Gas Y is more liquefiable than Gas X