Physical Chemistry Questions

1 For O O O AH 105 kJ mol What is the lowest energy photon that can in principle be used for the photodissociation of O into O and O What is the frequency of this photon What is the wavelength of this photon

4 A diatomic molecule X has a body centred cubic bcc structure with a cell edge of 300 pm The density of the molecule is 6 17 g cm The number of molecules present in 200 g of X is Avogadro constant N 6 x 10 3 mol JEE Main 2020 1 40 NA 3 2 NA 2 4 NA 4 8 NA

1 The enthalpy of hydrogenation of cyclohexene is 119 5 kJ mol If resonance energy of benzene is 150 4 kJ mol its enthalpy of hydrogenation would be A 208 1 kJ mol B 269 9 kJ mol C 358 5 kJ mol D 508 9 kJ mol

2 For the reaction taking places at certain temperature NH COONH s 2NH g CO g If equilibrium pressure is 3X bar then AG would be A RTln9 3RTX C 3 RTlnX B RTln4 3RTlnX D RTln4 3RTlnX

An element has a face centred cubic fcc structure with a cell edge of a The distance between the centres of two nearest tetrahedral voids in the lattice is JEE Main 2019 1 NEW a NON 3 a 2 N O 4 2a

Which of the following statements is false 1 o bond is shorter than that of bond 2 Bond energies of o and bonds are of the order of 264 and 347 kJ mol respectively Free rotation of atoms about o bond is allowed but not in case of bond T 4 bond results from lateral overlap of atomic orbitals

Solid State A solid A and B had NaCl type closed packed structure If the anion has a radius of 250 pm what should be the ideal radius of the cation Can a cation C having a radius of 180 pm be slipped into the tetrahedral site of the crystal of A B Give reasons for your answer KF crystallizes in the NaCl tyng

25 An element crystallises in a face centred cubic fcc unit cell with cell edge a The distance between the centres of two nearest octahedral voids in the crystal lattice is JEE Main 2020

Which primitive unit cell has unequal edge lengths a b c and all axial angles different from 90 JEE Main 2019 1 Hexagonal 2 Monoclinic 3 Triclinic 4 Tetragonal

QUESTION 4 Calculate the equilibrium constant of below reaction NH Cl aq Na2S aq H2O l NH3 H2O aq NaHS aq NaCl a Knew K and K of H S are 10 7 2 and 10 14 K of NH4OH is 10 4 76 and Kw 10 L

Rutherfords experiment which established the nuclear model of atom used a beam of A B particles which impinged on a metal foil and get absorbed B y rays which impinged on a metal foil and ejected electron C Helium atoms which impinged on a metal foil and got scattered D Helium nuclie which impinged on a metal foil and got scattered

Boron phosphide BP is a semiconductor and a hard abrasion resistance material It crystallises in a zinc blende structure formed from boron atoms in a fcc lattice and phosphorus atoms in tetrahedral holes Thus P atoms must be in 1 of the tetrahedral holes 1 2 of the octahedral holes 8 3 4 Equal to tetrahedral holes of the tetrahedral holes

Consider a ternary mixture in which 10 g acetic acid MW 60 and 18 g glucose MW 180 is dissolved in 90 g of water What is the mole fraction of acetic acid in mixture 6 155 5 158 4 155 9 160

Its C Different than the order May be same or different as compared to order 1 3 A gaseous compound A reacts by three independent first order process as shown in figure with rate constant 2 x 10 1 93 x 10 sec and 3 x 103 sec respectively for products B C and D respectively If initially pure A was taken in a closed container with P 8 atm then partial pressure of B in atm after 100 sec from start of experiment A 0 228 C 1 154 B 0 577 D none A g k k B g D g C g

Calculate the volume of O liberated at STP by 81 passing 5A current for 193 sec through acidified water 1 56 mL 3 158 mL 2 112 mL 4 965 mL PRIR 2912 1 5e 3 15 0500

Identify the incorrect statement 1 Gangue is an ore contaminated with undesired materials 2 The scientific and technological process used for isolation of the metal from its ore is known as metallurgy 3 Minerals are naturally occurring chemical substances in the earth s crust 4 Ores are minerals that may contain a metal

Atomic radius is of the order of 10 8 cm and nuclear radius is of the order of 10 13 cm Calculate what fraction of atom is occupied by nucleus With what velocity should an a particles travel towards the nucleus of a Cu atom co 12

Question No 43 An aqueous solution containing one mole per litre each of Cu NO3 2 AgNO3 Hg2 NO3 2 Mg NO3 2 is being electrolysed by using inert electrodes The value of standard potential are 0 79V E Ag Ag E 0 80V E H H 0 34V and E 2 3V With increasing voltage the sequence of deposition of metals on the cathode will be Options Ag Hg Cu Mg Mg Mg

Consider the conversion of O into O as 1 0 0 0 fast 11 O 0 20 slow One doubling the concentration of Os the rate of overall reaction becomes 1 1 times 3 3 times 2 2 times 4 4 times

Two solids A and B equilibria in a vessel A s X g 2Y g shows the following Kp 9x10 Kp2 B s Z g 2Y g What will be the total pressure over a mixture of A and B in atm A 0 45 C 0 35 B 0 60 D 0 75 4 5 10

What is the amount of heat in Joules absorbed by 18 g of water initially at room temperature heated to 100 C If 10 g of Cu is added to this water than decrease in temperature in Kelvin of water was found to be C p m for water 75 32 J mol K C p m for Cu 24 47 J mol K a 5649 369 c 5278 342 b d 5544 324 3425 425

What is the AG f Cr3 given AG following unbalanced reaction O g Cr s 197 5 kJ mol 214 5 kJ mol 287 1 kJ mol 351 3 kJ mol f H 0 1 Cr aq 237 19 kJ mol and AG acidic solution f H 0 kJ mol and the

Assertion A process is called adiabatic if the system does not exchange heat with the surroundings Reason It does not involve increase or decrease in temperature of the system a Assertion is correct reason is correct reason is a correct explanation for assertion b Assertion is correct reason is correct reason is not a correct explanation for assertion c Assertion is correct reason is incorrect d Assertion is incorrect reason is correct

11 Assertion A spherical water drop becomes flat on flat surface Reason It becomes flat due to gravity b a If both assertion and reason are true and reason is the correct explanation of assertion If both assertion and reason are true but reason is not the correct explanation of assertion c If assertion is true but reason is false d If both assertion and reason are false

Earlier Model of Atom Wave Theory 1 The mass to charge ratio for A iobns is 1 97 x 10 7 kg C 1 Calculate the mass of A atom 2 Atomic radius is of the order of 10 8 cm and nuclear radius is of the order of 10 13 of atom is occupied by nucleus cm Calcula

A pure sample of an element E is cut by knif e into perfect cubes If 7 5 x 1022 atoms are present in one such cube and a is edge lengt h of cube in cm then what will be the value o f a6 in cm6 Given Atomic mass of E 32 1023 N 6 x Density of element 4 3 g cm a 9 b 4 c 16 d 25

High penetration effect of ns electrons as compared to np electrons is responsible for Question Type Multiple Correct Type 1 2 Higher IE2 of Na as compared to Mg 3 Higher IE of Mg as compared to Al 4 Higher IE of P as compared to S Higher IE2 of B as compared to C

5 A crystal is made up of metal ions M and M and oxide ions Oxide ions form a ccp lattice structure The cation M occupies 50 of octahedral voids and the cation M occupies 12 5 of tetrahedral voids of oxide lattice The oxidation numbers of M and M are respectively JEE Main 2020 1 3 1 2 4 2 4 2 4 3 1 3

f Amount of gas adsorbed or MORE THAN ONE correct answer The given graphs 2 data I II III and IV represent general trends observed for different physisorption and chemisorption processes under mild conditions of temperature and pressure Which of the following choice s about 1 II III and IV is are correct 200 K 250 K P I is physisorption and II is chemisorption IV is chemisorption and II is chemisorption paganapie 2 jo jasnewy Potential Energy 7 ESTION BANK Ed Distance of molecule from the surface te 150 kJ mal i B I is physisorption and III is chemisorption

Which of the following statements is incorrect 8 for the reaction Excess of KI reacts with CuSO4 solution and NaS O3 solution is added to it 1 Evolved I is reduced 2 Cul is formed 3 Na S O3 is oxidised 4 Cu Io is formed

For a sequential reaction K 0 1386 min A B K 1 386 x 10 min 1 C D K 1 386 107 min K 6 93 10 0 min 1 Starting with E pure A initially concentration 1M what will be concentration of D after 10 min assuming steady state is obtained Question Type Single Correct Type 10 13 M

4A n factors n n and n respectively During titration with an oxidizing agent Let at t 0 volume used of reagent be V Let at t t volume used of reagent be V Let at t volume used of reagent be V The rate constant for above action if only and Care participa C K 78 is taking place 28 3C following first order kinetics if all A B and C are oxidisable with 14 2 302 BK V C K The rate constant for above reaction if all are participating in titrations 2 303 V A K log V t 2 303 t 2 303 log log Mitrations REVIEW BOOKLET 2021 JEEA PART 4 CHEMISTRY V 4n 2n 3n V 3n 2n 3n V n MEGACOSM

A 600 W mercury lamp emits monochromatic radiation of wavelength 331 3 nm How many photons are emitted from the lamp per second h 6 6260 10 34 Js velocity of light 3 10 ms A 1 10 9 C 1 10 B 1 1020 D 1 1023 A A

What volume of 4 molar NaOH can be prepared from 5 molar 2 litre solution of NaOH 250 litre 2500 ml 5000 ml

28 If average molecular wt of air is 29 then assuming N2 and O gases are there which options 2 are correct regarding composition of air iii 72 41 by mass of N 2 only ii is correct b d both i and ii are correct 2 i 75 by mass of N ii 75 by moles N a only i is correct c both ii and iii are correct

2 F electricity was passed through molten FeO Weight of iron metal Atomic wt 56 deposited at cathode in g is 112 84 56 28

atomic volume that is occupied by nucleus is kx 10 The value of k is Ethylene oxide C H O is manufactured by burning of ethylene in air 2C H O 2C H O 60 g of ethylene oxide is obtained from 42 g of ethyline Calculate the precentage yield

17 Calculate the weight of CO having the same number of oxygen atoms as are present in 2 of CO 28 g 18 What is the molecular mass of substance each molecule of which contains 4 atoms of can parts of Mass

a Radius ratio of an ionic compound is 0 524 The structure of the above ionic compound is of 2 Points b In rock salt structure the number of CI ion required to form cubic close packed lattice is while number of Na ions required to fill the vacant octahedral sites formed by CI is

2 A sample of gas has a pressure of 0 27 atm and 54 3 mL The container is then compressed at constant temperature until the volume is reduced to 12 6 mL WHAT is the new pressure of the gas in the container

Correct for the following graph is are AG AI O ALO 2Mg O 2MgO 1673 T K 1 Mg will be good reducing agent below 1673 2 Al will be good reducing agent below 1673 3 Al O3 will be good reducing agent after 1673

1 Discusss the similarities and differences between a Is and a 2s orbital 2 Which quantum number tends to specify the orientation in space for an orbital 3 Which is the first energy level containing f orbitals 4 What is the relationship between wavelength and the momentum of a particle 5 What is the physical significance y of y and 5 What are degenerate orbitals

Select the rate law that corresponds to data shown for the following reaction 1994 A B products Exp B 1 0 035 2 0 070 3 0 035 0 070 A 0 012 0 024 0 024 4 0 012 a rate k B b rate k B 4 c rate k A B d rate k A B Initial rate 0 1 0 8 0 1 0 8

By a sample of ground state atomic hydrogen UV light of energy spectrum Orrect Answer 5 00 13 6 x 48 eV 49 is absorbed How many different wavelengths will be observed in Balmer region of hydrogen quanta

Cesium chloride forms a body centered cubic lattice Cesium and chloride ions are in contact alon body diagonal of the unit cell The length of the side of the unit cell is 412 pm and Cl ion has a rad 181 pm Calculate the radius of Cstion

30 Three mole of an ideal gas is taken through the process ABC as shown in the figure The total work done by the gas is T 27 T P 1 2 RTo In2 3 12 RTo In2 B 2P 8P P 2 4 RT In2 4 4 RTo In2 1 3 35 Am firs pip OV res 1

How to memorize this When we are asked to write electronic configuration of big ger elements what can be done to solve the question wit hin a minute Following is the increasing order of the energy of the orbit 18 25 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4 5d 6p 7s This order can be easily remembered in the following way 19 35 45 58 68 20 3P Ap SP op 3d 4d 54 6d Af 5f

For a consecutive reaction R A k B R K If initial concentration of R is 100 M and k k 1 0 15 what is the value of tmax Given k 4 0x10 2 min 1 R3 80 55 min 55 80 min

2 If the concentration of the herbicide atrazine commonly used in corn production in a water sample is 0 140 mg L how many parts per billion by volume are present 3 The current EPA maximum contaminant level of herbicide atrazine is 3 0 ppb by mass What is the maximum mass of atrazine allowed by the EPA per 1 0 kg of drinking water 4 The regulatory limit set by the EPA for the lead contaminant level is 15 parts per billion by mass What is the maximum mass in grams of lead in 2 0 gallon of drinking water that still satisfies the EPA regulatory limit The density of drinking water is 0 997 g mL

5 in PP3 P has a lone pair of electrons 3 dic isame Kse values of 6 2 x 10 13 at room temperature Which NEET 2016 MY and NY3 two nearly insoluble salts have the statement would be true in regard to MY and Nyns of 1 The addition of the salt of KY to solution of MY and NY will have no effect on their solubilities 2 The molar solubilities of MY and NY3 in water are identical 3 The molar solubility of MY in water is less than that of NY 4 The salts MY and NY are more soluble in 0 5 M KY than in pure water 3 Sol Answer 3