Physical Chemistry Questions

5 For the chemical reaction XY the standard reaction Gibbs energy depends on temperature T in K as A G in kJ mol 120 3 8 The major component of the reaction mixture at Tis a Yif T 280 K b Xif T 350 K c Xif T 315 K d Yif T 300 K JEE Main 2019 11 Jan Shift 1

When mercuric iodide is added to the aqueous solution of KI then the 1 Freezing point is raised 2 Freezing point is lowered 3 Freezing point does not change 4 Boiling point does not change

There are four solvents A A Ag and A4 The dielectric constants of the solvents follow the order Ag A A A Among them only A and A are capable of forming hydrogen bonds Which of the solvents will be most suitable for Sw1 reactions A A C A3 B A D A4

20 iv The diagram shows a respirometer used to meansure oxygen uptake by woodi Syringe Perforated basket Woodice Filter paper wick X Manometer What is X a Buffer solution to control the pH b Lime water to indicate the presence of carbon dioxide c Potassium hydroxide solution to absorb carbon dioxide d Water to control the humidity

Select the correct option s about valence Bond Theory regarding co ordination compounds It does not explain visible spectra of complexes It is not able to explain diamagnetic behaviour of Co H O 6 Cl3 even Co is paramagnetic It is unable to differentiate between weak and strong field ligands It makes exact predictions regarding the tetrahedral and square planar structures of 4 coordinate complexes

Total vapour pressure of mixture of 1 mol P 150 torr and 2 mol Y P 300 torr is 24 torr In this case 1 There is a negative deviation from Raoult s law 2 There is a positive deviation from Raoult s law 3 There is no deviation from Raoult s law 4 Can not be decided

1 Which of the following compounds has a negative enthalpy of solution 1 KCI 2 KBr small size of peion it here maxim Eve enthalpy of Solution 3 KF 4 KI 22 X X AH 720k1 mol 1

Glycerol on oxidation with dil HNO3 gives 1 tartronic acid 2 mesoxalic acid 3 oxalic acid 4 glyceric acid 2 3 CH 0 How many moles of HI consumed in above reaction 1 1 2 2 3 3 4 4 CH CH CH 5 OH Falcohol CH Find missing reagents 1 x LiAlH4 y NaBH4 2 x LIAIH4 AICI3 y LIAIH4 3 x LIAIH4 Y LIAIH4 AICI3 4 x H Ni y H Pt 3 Aluminium isopropoxide 4 Acetone CH CH OCH 1 200 2 2 HCOOH CH CH CH CH CH OH 2 akohol H COH CH OH on heating with per iodic acid gives I 3 CHO 4 Which of the following reagents would distinguish cis cyclopenta 1 2 diol from the trans isomer 1 ozone 2 MnO 4 6 7 H c 0 2 I CH Mgl i H O The compound Y in the above sequence is 1 2 Methyl 2 phenyl 1 propanol 2 2 Phenyl 2 propanol 3 Acetophenone 4 2 Methyl 1 Phenyl 2 propanol 8 What is X 1 CHO 3 4 CH 3 CH3 CH B Predominant OH CH MgBr excess PBes X H O OH OH Cu 575 K CH3 Y x OH OH

15 The variation of the boiling points of the hydrogen halides is in the order HF HI HBr HCI What explains the higher boiling point of hydrogen fluoride 1 The bond energy of HF molecules is greater than in other hydrogen halides 2 The effect of nuclear shielding is much reduced in fluorine which polarises the HF molecule 3 The electronegativity of fluorine is much higher than for other elements in the group 4 There is strong hydrogen bonding between HF molecules

The compound has two atoms X and Y its cubic crystal structure X atom in the water at the corners of the unit cell and Y atomic work is at the centre Its simplest formula is 1 x y 2 XY 3 XY 4 XXY

The bond enthalpies of H X and HX are in the ratio of 2 1 2 If enthalpy of formation of HX is 50 kJ mol the bond enthalpy of X is A B C 100 kJ mol 1 200 kJ mol 1 300 kJ mol 1 Correct Answer

2 S 3022SO3 AH 791 4 kJ When 6 4 g of Oxygen are reacted with excess sulfur and 52 760 J are released What is the q value of the reaction If this reaction occurs in 300 ml of water that began at 25 3 C what would be the final temp

A commercially valuable paint and adhesive stripper DMSO can be prepared by the reaction of exygen with dimethyl anders using a s of one mole oxygen to two moles of the sulfide O 2 CH S 2 CH SO atomic mass of S C and O are 32 12 and 16 respectively Question 28 If the process is 100 efficient weight of O in gram that is used up with 65 g of dimethyl sulfide DA15 46 g B 16 77 g Oc 14 64 g b 15 89 g

Select the correct statement s regarding following galvanic cell taken at temperature TK Pt H g 1 bar HCI 10 3 M AgCl s Ag s 2 303RT Given that 0 06volt F Eg AgCl Cr 0 18volt Cell potential of this cell is 0 54 volt During discharging H g converts into H aq H g is obtained at cathode during working of this galvanic cell DE Ag Ag is equal to 0 78 volt if Ksp of AgCl is 1 10 10

Mean bond enthalpy of C H bond is 416 kJ mol 1 AaHo fo CH4 is 416 kJ mol 1 416 kJ mol 1 1664 kJ mol 1 1664 kJ mol 1

14 Which one of the following orders is correct for the bond dissociation enthalpy of halogen molecules Fo 010 YOU O 019

32 The correct order of energies of d orbitals of metal ion in a 32 square plannar complex is 1 d d d 2 d d d d d 3 d d ayd

At 300K the reactions having following values of thermodynamic parameters which occur spontaneously a AG 400kJ mol 1 b AH 200 kJ mol 1 AS 4 JK 1 mol 1 c AH 200 J mol 1 AS 4 JK 1 mol 1 d AH 200 kJ mol 1 AS 40 JK 1 mol 1 A B a c d a b c

4 In Na Fe CN NO sodium nitroprusside ipt 1 oxidation state of Fe is 2 2 this has NO as ligand 3 both are correct 4 none is correct

b a ground state of Na e excited state of Mg d excited state of Al 9 Ionisation potential of hydrogen atom is 13 6 eV Hydrogen atom in the ground state are excited by monochromatic light of energy 12 1 eV The spectral lines emitted by hydrogen according to Bohr s theory will be CBSE PMT 1992 a one three My b two d four 1 81 residing in a

A body of mass 2 kg moving with a velocity i 2j3k ms collides with another body of mass 3 kg moving with a velocity 21 3 k ms 14 If they stick together the velocity in ms of the composite body is 1 8 73 3k 2 4i j 3k 3 1 8i j k 4 4i 73 3k 120

T Y B Sc I Physical Chemistry 8 The half life period of a radioactive element is 120 days After 600 days one gram of the element will reduce to 41 g b The unit of a rate of reaction is a 5 1 b mol s The order of the a 0 16 d g 6 mol 1 1

Write the cell reaction and calculate the e m f of the following cell at 298 K Sn s Sn 0 004 M H 0 020 M H2 g 1 bar Pt s Given E Sn Sn 0 14 V Log 10 1

6 The decomposition of N O in carbon tetrachloride was followed by measuring the volume of O gas evolved 2N 0 CC1 2N O4 CC14 O g The maximum volume of 0 gas obtained was 100 cm In 500 minutes 90 cm of O were evolved The first order rate constant in min for the disappearance of N 0 is 2 303 2 303 b log c 500 500 2 303 100 500 90 log 90 100 d 100 10 500 TEST Platinum fe c 63 Th 8

A solid has CCP arrangement having atoms A B and C If A atoms are present at face centres B at corners and C atoms occupy 50 tetrahedral voids then molecular formula of solid will be A 80 A3B4C AB3C4 C A4BC3

A proton accelerated from rest through a potential difference of V volts has a wavelength associated with it An alpha particle in order to have the same wavelength must be accelerated from rest through a potential difference of A V volt C 2V volt B 4V volt V 8 D volt

3 Which is incorrectly given according to order indicated 1 F2 C12 Br2 12 Oxidising power 2 HI HBr HCI HF Acidic strength 3 F2 C12 Br2 12 Bond dissociation enthalpy 4 HF HI HBr HCI Boiling point

8 9 11 100 ml of its 0 05 N solution is a 2 9424 g c 1 4712g 12 a 2 N c 39 6 N 10 Molarity of 0 2N H SO4 is a 0 2 c 0 6 36g water and 828g ethyl alcohol form an ideal solution The mole fraction of water in it is MP PMT 2003 a 1 0 c 0 4 Conc H SO4 has a density of 1 98 gm ml and is 98 H SO4 by weight Its normality is MP PET 2002 c 77 68 JIPMER 2002 b 0 4904 g d 0 2452 g 20 80 d b 0 7 d 0 1 The mole fraction of water in 20 aqueous solution of H O is EAMCET 1993 a b 19 8 N d 98 N b 0 4 d 0 1 68 77 80 20 prepare How many gm of H SO is present in 0 25 gm mole of H SO4 CPMT 1990 a 24 5 c 0 25 b 2 45 d 0 245 13 1 0 gm of pure calcium carbonate was found to require 50 ml of dilute HCl for complete reaction The strength of the HCl solution is given by CPMT 1986 a 4 N c 0 4 N b 2 N d 0 2 N 14 10 grams of a solute is dissolved in 90 grams of a solvent Its mass percent in solution is a 0 01 b 11 1

The above set up has been repeated four times wit 4 different aqueous solution of same non volati solute with different concentrations The loss weight of solution in container is in order D B C A Arrange A B C D in terms of concentrati of solute 1 D B C A 3 U 1 C Moist Air 2 A B C D 1

5 In Bohr series of lines of hydrogen spectrum the third line from the red end corresponds to which one of the following inter orbit jumps of the electron for Bohr orbits in an atom of hydrogen a 32 c 4 1 5 5 2 d 2 5 length of a tennis ball of mass 60g

c linear increase with increase of temperature d linear decrease with increase of temperature The plot of log k vs I T is linear with a slope of a Ea R b Ea R C the c Ea 2 303R a Ea 2

53 Three isotopes of an element have mass numbers m m 1 and m 2 If the mean mass number is m 0 5 then which of the following ratios may be accepted for m m 1 m 2 in that order k a 1 1 1 c 3 2 1 54 The radii of 5 4 1 1 d 2 1 1

101 A bottle of H PO solution contains 70 w w acid If the density of the solution is 1 54 g cm the volume of the H3PO4 solution required to prepare 1 L of 1 N solution is 1 90mL 2 45 mL 3 30 mL 4 23 mL

What should be the value of Kc for the reaction 2SO2 g O g 2SO3 g If the amounts are SO3 48 g SO 12 8 g and O 9 6 g at equilibrium and the volume of the container is one litre Question Type Single Correct Type 1 2 3 64 30 42

22 Select the correct statement s from the following 1 Fluorine displaces other halogens from the corresponding halides 2 Fluorine reacts slowly with halogens 3 Fluorine does not decompose water 4 Except fluorine other halogens directly combine with carbon

15 The activation energy in a chemical reaction is defined as the difference in average energies of reactants and products b the difference in average energies of reactants and activated complex c the difference in average energies of products and activated complex d the sum of energies of rea tants and products

In hexagonal close packing of sphere in three dimensions A In one unit cell there are 12 octahedral voids and all are completely inside the hexagonal unit cell B In one unit cell there are six octahedral voids and all are completely inside the hexagonal unit cell C In one unit cell there are six octahedral void and of which three are completely inside the unit cell and other three are from contributions of octahedral voids which are partially inside the hexagonal unit cell D In one unit cell 6 tetrahedral voids are completely inside the hexagonal unit cell

Among the following process ASsys is positive for Freezing of water Stretching of rubber band Condensation of vapours Diffusion of gases E

dt dt 2 The rate constant does not depend upon concentration for reaction whose order is c second a zero b first d third 3 If the rate law does not contain a concentration term then the order is b first Seco econd d third 37

The electron affinity of fluorine is less than that of chlorine because A The incoming electron enters the 3p orbital in fluorine B The incoming electron enters the 2p orbitals in fluorine and 3p orbital in chlorine The electron density in fluorine is higher D Fluorine has lower ionisation potential than chlorine

Two moles of N O4 is heated to form NO and 0 As soon as NO and O are formed they react to form N205 Two equilibria N O4 2NO 0 2NO 20 N O5 Are simultaneously established At equilibrium the degree of dissociation of N O4 was found to 50 Which of the following is correct at equilibrium 1 NO 0 2 2 N O4 NO 0 N 05 2 3 NO 0 N2O4 N O5 4 N O5 O2 NO 2 2

The rate constant of an exothermic reaction follows exponential increase with increase of temperature b exponential decrease with increase of temperature c linear increase with increase of temperature d linear decrease with increase of temperature The plot of log k vs T is linear with a slope of

Q2 Air at 45 C and 25 relative humidity enters water spray tower at rate of 90 m hr The air is adiabatically humidified to 50 relative humidity Use psychrometric chart to find 1 Outlet temperature of the humidified air 2 Rate of water evaporation in the water spray tower

2 d TB 0 5eV 57 The frequency v of certain line of the Lyman series the atomic spectrum of hydrogen satisfies the follow conditions 1 It is the sum of the frequencies of another Lyman ii It is the sum of the frequencies of a certain line and a Balmer line Lyman line and a Paschen line

6 Consider the following information Atomic radius of Li Atomic radius of Be x Atomic radius of Na Atomic radius of Li y Atomic radius of K Atomic radius of Na Z then correct relation between x y and z 1 x y z 2 x y z 3 z x y

112 During the titration of a weak diprotic acid H A against a strong base NaOH the pH of the solution half way to the first equivalent point and that at the first equivalent point are given respectively by a pK and pK a a c pKa and PK pKa 2 13 In which of the following cases is the solution of AgCl unsaturated pK a q b KC and 92 PK pk a 2 d pK and pK a2 92

For thermal decomposition of NH4NO3 s The correct information s is are NH4NO3 s AH N O g 2H O g at TK Patm Heat of reaction is positive Entropy change of the reaction must be A H T Heat of reaction at constant volume is equal to A H 3 RT DAG of this reaction may be negative at high temperature

At a certain temperature the half life periods for the catalytic decomposition of NH were found to be as follows Pressue mm Hg 50 100 200 Half life period hrs 3 52 1 76 0 88 What will be the pressure when the half life perriod is 1 5 hours

a zero 6 integral c fractional a negat 5 If the activation energy of a reaction decreases then the rate of reaction a decreases b remains constant increases d becomes zero 7 The rate constant of a first order reaction depends on the

neet prep CH CH NH 129 H IV 1 2 and 4 2 2 and 3 3 2 3 and 4 4 Only 2 High Yielding Test Series Full Test 2 converted to Given HCOOH 1 22 g cc 1 0 0185 2 0 0073 3 0 074 4 0 037 CH CH NH NH The value of K for self ionization of formic acid is 10 4 at room temperature What percentage of formic acid is formate ion Contact Number 9667591930 8527521718 130 The azeotropic mixture of water and ethanol boils at 78 15 C When this mixture is distilled it is possible to obtain 1 pure H O 2 pure C H OH 3 pure H O as well as pure C HOH 4 neither H O nor C H5OH in their pure state 131 The net work done for an ideal gas is given as 1 3PV 2 3PV 3 PV 4 Zero 132 p v 133 Y 4p 3v Aluminium reacts with concentrated HCI and concentrated NaOH to liberate the Z p 3v gases respectively 1 H and H 2 0 and O 3 0 and H 4 H and O 2 1 3 2 4 0 Using MO theory predict which of the following species has the shortest bond length 1 0 2 0 3 02 4 0 2 134 The oxidation state of sodium in sodium amalgam is 1 1 135 Lactic acid on oxidation by alkaline potassium permanganate gives