Physical Chemistry Questions

Be sure to answer all parts Click in the answer box to activate each palette Write the balanced equation and solubility product expression for the solubility equilibrium of Mn3 PO4 2 Include physical states and use correct subscripts and superscripts Ksp expression

An exothermic chemical reaction proceeds by two stages Reactants stage 2 Intermediate Products The activation energy of stage 1 is 50 kJ mol The overall enthalpy change for the reaction is 100 kJ mol Which diagram could represent the energy level diagram for the reaction a E 200 150 100 c E 50 200 150 stage 1 100 50 R P Progress of reaction R P Progress of reaction 200 150 b E 100 50 P R Progress of reaction 200 150 d E 100 50 Me R Progress of reaction

The standard potentials for two nonadjacent species can also be calculated by using the concept that AG as an additive property but potential is not an additive property and AG nFE If a given oxidation state is a stronger oxidising agent than in the next higher oxidation state disproportionation can occur The reverse of disproportionation is called comproportionation The relative stabilities of the oxidation state can also be understood by drawing a graph of AG F against oxidation state known as Frost diagram choosing the stability of zero oxidation state arbitrarily as zero The most stable oxidation state of a species lies lowest in the diagram Disproportionation is spontaneous if the species lies above a straight line joining its two products species Question 32 Which of the following couple have same value of potential at pH 0 and pH 14 Options CIO CIO

similar amounts of reactants and products 14 a H O 03 H O 20 b H O Ag 0 2Ag H O 0 Role of hydrogen peroxide in the above reactions is respectively 1 oxidizing in a and reducing in b 2 reducing in a and oxidizing in b 3 reducing in a and b 4 oxidizing in a and b

Excess sodium sulfide is added to 79 8 mL of silver nitrate solution The precipitate is collected and dries and the mass is found to be 4 51 g What wa the concentration of the silver nitrate solution Select one a 0 456 b 0 350 X c 0 650 d 0 0364 e 0 450

Fe e Fe EF 0 77V 2 0 30 V 1 0 057 V 3 0 30 V 4 0 057 V 17 Approximate atomic weight of an element is 26 89 If its equivalent weight is 8 9 the exact atomic weight of element would be 1 26 89 2 8 9 3 17 8 4 26 7

5 20 When 1L of CO2 is heated with graphite the volume of the gases collected is 1 8L What will be the number of moles of CO produced at STP Final Results 0 0 0357

Calculate the osmotic pressure at 25 C of an aqueous solution of 1 00 g L of a protein having molar mass 1 85x10 g mol

On adding AgNO3 solution to KI solution a negatively charged colloidal sol will be formed in which of the following conditions 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 KI 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

What is the mass of ammonium chloride in a 1 73 M ammonium chloride aqueous solution at 20 C Density of the solution is 1 0257 g mL Select one a 0 594 b 1 68 c 1 85 X d 9 00

2 NO g Cl g 2 NOCI g was studied at 10 C The following results were obtained where d C1 dt Rate Initial Rate NO mol L Cl mol L mol L min L 1 in a 0 11 0 11 0 22 What is the rate law 0 17 0 34 0 34 Use k for the rate constant Rate b What is the value of the rate constant L mol 2 Rate constant 0 36 0 71 2 80 min 1

AAJ KA TOPPER k 1 72Kkemol a freezing point depression of 2K is observed The van t Hoff

If the rate constant of a chemical reaction at 500K 700K are 0 02s 1 and 0 07 s 1 respectively its activation energy is In7 1 9 In2 0 7 R 8J mol K O 1680 kJ mol 16800 J mol 1680 cal mol O 16 8 kcal mol

4 NH NH NH 3 NH NH NH Which of the following on heating with aqueous KOH produces acetaldehyde 1 CH CH CI 2 CH CICH CI 3 CH CHCI 4 CH COCI During extraction of silver from cyanide process which of the following is formed 1 Na Ag CN 2 Na Ag CN 3 Na Ag CN 4 None of these

1 1 2 0 3 1 4 2 The alkali metals dissolve in ammonia to give a deep blue solution which is conducting in nature M x y NH M NH 2 c NH 1 The blue colour is due to ammoniated electron 2 The solution is paramagnetic 3 The blue colour changes to brown on standing 4 In concentrated solution blue colour changes to bronze and becomes diamagnetic

2 Describe briefly what happens in an unmagnetised ferromagnetic substance when it is magnetised by means of an externally applied magnetic field Provide a brief discussion of the hysteresis loop as part of your description 4 Points th Na 1 and 2

Assertion Vapour pressure of water is less than 1 013 bar at 373 K Reason Water boils at 373 K as the vapour pressure at this temperature becomes equal to atmospheric pressure A B C D Assertion and reason both are correct statements and reason is correct explanation for assertion Assertion and reason both are correct statements but reason is not correct explanation for assertion Assertion is correct statement but reason is wrong statement Assertion is wrong statement but is correct statement

a more b less c medium d high 5 In AAS high concentrations of gaseous atoms cause of absorption lines a narrowing b broadening c resonance In AAS is obeyed over a wide range of concentrations DL c Beer s law 7 d sputtering d Bouguer s law

3 1 mole of NO and 2 moles of CO are enclosed in a one litre vessel to attain the following equilibrium NO CO NO CO It was estimated that at the equilibrium 25 of initial amount of CO is consumed The equilibrium constant K is 1 1 3 114 2 1 2 4 1 3

and 6 Two buffers X the salt NaA Both the buffers are 0 50 Min respectively are prepared from acid HA 2 HA What would be the pH of the solution obtained by mixing equal volumes of the two buffers K 1 0 105 A 4 7033 C 6 7033 B 5 7033 D 8 7033

9 0 IV Distillation of calcium benzoate 1 I and IV 2 I and II 3 I and III 4 III and IV The relative abundance of two isotopes of an element with atomic weight 85 and 87 is 75 and 25 respectively Then calculate the average atomic weight of element 1 86 0 2 85 5 3 75 5 4 40 0 Which given compound can be reduced with zinc amalgum and hydrochloric acid

3 In N the N N bond weakness 4 N becomes paramagnetic 5 The equivalent conduce of 1M benzoic acid is 12 8ohm cm and if the conductanc of benzoate ion and Hion at infinite dilution are 42 and 288 42ohm cm respectively Then its degree of dissociation is 1 0 039 2 3 9 3 0 35 7 Which is true for internal energy of system is 4 39

22 Which of the following compound does undergo aldol condensation 1 HCHO CH I 2 CH C CHO 1 CH 3 CC1 CHO OF AUG

es of an ideal gas at 200 K is compressed reversibly and adiabatically untill final temperature reaches 250 K If molas nstant volume is 27 cal mol K find work 3050 cal 3550 cal 4050 cal

CHEMISTRY For a photochemical reaction AB 1 0x105 mole of B were formed on absorbing 1 2x10 quant each of 2 360 nm The quantum efficiency is given by 1 0 50 2 1 3 0 1 4 0 2

The reaction Quotient Qe for the reaction N2 g 3H2 g 2NH3 g is given as Qc NH3 2 N H The reaction will proceed in forward direction if B Qc Kc Qc Kc Qc Kc

The volume of 2 8 g of carbon monoxide at 27 C and 0 821 atm pressure is R 0 0821 lit atm K mol 0 3 litre 1 5 litre 3 litre CORRECT ANSWER PI

2 Two beakers of capacity 500 mL were taken One of these beakers labelled as A was filled with 400 ml water whereas the beaker labelled B was filled with 400 mL of 2 M solution of NaCl At the same temperature both the beakers were placed in closed containers of same material and same capacity as shown in figure A B Water NaCl solution At a given temperature which of the following statements is correct about the vapour pressure of pure water and that of NaCl solution a Vapour pressure in container A is more than that in container B b Vapour pressure in container A is less than that in container B c Vapour pressure is equal in both the containers d Vapour pressure in containor R is twice the

a gratings b prisms c filters 6 Spectral interference is much when monochromators are used a less c very high d low b high Q 2 State whether true or false Flomo omiccion is primarily used for quantitative determination of alkali and alkal

Which one of the following statements is incorrect in relation to ionisation enthalpy A B lonisation enthalpy increases for each successive electron D The greater increase in ionisation enthalpy is experienced on removal of electron from core noble gas configuration End of valence electrons C is marked by a big jump in ionisation enthalpy Removal of electron from orbitals bearing lower n value is easier than from an orbital having

The amount of energy when million atoms of iodine are completely converted into I ions in the vapour state according to the equation 1 8 er is 4 9x10 J Calculate the electron gain enthalpy of iodine in terms of eV atom A 3 06 B 3 06 C 126

Find the ApH initial pH final pH when 100 ml 0 01 M HCI is added in a solution containig 0 1 m molesof NaHCO3 solution of negligible volume Ka 107 Ka 10 11 for H CO3 1 6 2 log3 2 6 log3 3 6 2log2 4 6 21 93

An inorganic salt is lemon yellow in colour It becomes orange in colour like methyl orange when it is acidic and again becomes yellow when it is alkaline The inorganic salt will be Question Type Single Correct Type 1 Copper nitrate 2 Ferric chloride 3 Potassium chromate

K 2min X g Y g K 30min Z g If decomposition of X g is carried out in sealed flask partial pressure of Y after very l time is 100 mmHg then correct option is are take In2 0 7 A Initial pressure of X was 1600 mmHg 0 7 B minutes required for P to become 400 mmHg 16 C Net rate constant for overall reaction is 1 32 P after half life of reaction is 50 mmHg min

c photovoltaic cells The intensity of spectral lines in different parts of the flame a varies b remains same d remain unchanged c changes In flame most of the lines emitted are from the AUNVR

96 Two possible stereo structures of CH3CHOH COOH which are optically active are called 1 Diastereomers 2 3 4 Mesomers Atropisomers Enantiomers 97 4 100 Conside find ou linear 1 CH 2 CH

Which one of the following pairs is iso structural i e having the same shape and hybridization 1 BCI and BrCl3 2 NH3 and NO3 3 NF3 and BF3 4 BF4 and NH 117 1 2 3 4 121 T ec 1 2

nitrogen in the soil is 1 37 33 neet prep High Yielding Test Series Part Test 4 1 help in the precipitation of AgCl 2 increases the solubility product of AgCl The Lassaigne s extract is boiled with conc HNO while testing for halogens Because 3 increase the concentration of NO ions IM CONCE Contact Number 9667591930 8527521718 CH3 H H H Page H

Ib The R and S enantiomers of an optically active sh compound differ in 1 their optical rotation of plane polarized light 2 their reactivity with chiral reagents 3 their solubility in achiral reagents 4 their melting points 108 C

a narrowing b broadening 7 In AAS is obeyed over a wide range of a Lambert s law b Nernst law B For alkali metals laboratory type lamps c resonance d sputtering concentrations c Beer s law d Bouguer s law can be used as a source instead of hollow

Calculate the rate of condensation on a 1 5 by 1 5 m vertical plate maintained at 40 and exposed to saturated water vapor at 55 F h fg 2376 kJ kg at 55 F A vertical plate 40 by 40 cm is exposed to saturated vanor ammonia at 38

P is the probability of finding the 1s electron of hydrogen atom in a spherical shell of infinitesimal thickness dr at a distance r from the nucleus The volume of this shell is 4tr dr The qualitative sketch of the dependence of P on ris a P 0 c P r b P 0 d P 0 1 r

Select the incorrect option when a lead storage battery is discharged A B SO is evolved Lead sulphate is produced at both electrodes Sulphuric acid is consumed Water is formed

A generic solid X has a molar mass of 55 9 g mol In a constant pressure calorimeter 26 4 g of X is dissolved in 369 g of water at 23 00 C X s X m The temperature of the resulting solution rises to 26 40 C Assume the solution has the same specific heat as water 4 184 J g C and that there is negligible heat loss to the surroundings How much heat was absorbed by the solution What is the enthalpy of the reaction kl

Solvelancer Test For the given organic compound select the correct IUPAC name s from the following CH CH CH CH CH CH CH CH CH CH CH CH T CH Solvelancer Test a 5 2 Methyl propyl nonane b 4 butyl 2 methyloctane c 5 Isobutyl nonane a Only a b Only b c Both a c d Both b c

Two complexes A MW 245 g mol B MW 364 g mol Two solutions was prepared from 0 0615 g A in 100 mL water and the second solution prepared from 0 113 g B in 100 mL water The specifi conductivity of A is 625 s and B is 1650 s What is the number of ions for each complex

116 Identify the reagent from the following list which can easily distinguish between 1 butyne and 2 butyne 1 bromine CCl4 2 H Lindlar catalyst 3 dilute H SO4 HgSO4 4 ammonical cuprous chloride 117 121 1 1 2 3 4 122

c Graham s law 8 In controlled cathode potential electrolysis the third electrode used is a working electrode c counter electrode b reference electrode d auxillary electrode

Consider the following reaction 2HI g H g 12 g At 500 K the he equilibrium constant Kp is 0 063 A 1 50 L container at 500 K is initially filled with 0 809 mol of HI and allowed to equilibrate What is the equilibrium concentration of 12 g a 0 54 M b 0 14 M c none of the answers given are correct d 0 090 M e 0 18 M

Consider the reaction 2 S s 3 02 g 2 SO3 g Initially 1 0 moles of each reactant was placed into a 2 0 L flask At equilibrium 0 10 moles of SO3 g had formed What is the value of Kc for the reaction at this temperature Hints check the states of the substances in the reaction carefully and remember to think about which units you need to work in