Physical Chemistry Questions

Q47 Compound contains atoms2 2 elements A B and C If the oxidation of three number of A is 2 B is 5 and that of C is 2 the possible formula of the compound is A2 21HED A B C 3x 40 CBA3 BC4 2 C A3 B4C 2 D ABC A A BC3 2 A BC 3x 10 8 3x 40 4 2 5 2 Q 47 a 3x 10 16 02 12 A A BC3 2 B A3 BC4 2 C A3 B4C 2 D ABC 2 Q 48 The General mechanism of electrophilic substitution has key step 2 5 2 u 3 A B 31 2 5 a F 2x 10 6 0 2x 40 edg 6 48 31 46 U 10 6 0 METRO

s 1 ar th in of M L requires 0 5 g of NaOH for complete neutralisation The number of replaceable hydrogen atoms and the molecular weight of A would be Mw of acid 96 a 2 94 d 4 92 b 1 95 c 3 93 55 A mixed solution of potassium hydroxide and sodium carbonate required 15 mL of an N 20 HCl solution when titrated with phenolphthalein as an indicator But the same amount of the solution when titrated with methyl orange as indicator required 25 mL of the same acid The amount of KOH present in the solution is a 0 014 g b 0 14 g c 0 028 g d 1 4 g 56 25 0 g of FeSO4 7H O was dissolved in water containing dilute H SO4 and the volume was made up to 1 0 L 25 0 mL of this solution required 20 mL of an N 10 KMnO solution for complete oxidation The percentage of FeSO4 7H O in the acid solution is 4 a 78 b 98 d 79 57 A 0 13 g of a specimen containing MnO is treated with iodide ions If iodine liberated requires 30 0 mL of 0 075 M solution of Na S O3 the percentage of MnO in the mineral is ho c 89 a 75 3 b 85 3 c 95 3 d None A Mod 58 The mass of K Cr O required to produce 5 0 L CO at 77 C and 0 82 atm pressure from excess of oxalic acid and volume of 0 1 N NaOH required to neutralise the CO evolved respectively are 24 31 a 7 g 2 86 L 101561 6 9 Boas b 5 g 1 86 L Jam d None c 4 g 0 86 L 59 A mixture of Na C O4 and KHC O4 H C O4 required equal o of 02 M KMnO and 0 2 M NaOH separately

12 The conductivities at infinite dilution of NH CI NaOH and NaCl are 130 218 120 ohm 1cm eq 1 If N equivalent conductance of solution of NH OH 100 is 10 then degree of dissociation of NH OH at this dilution is 1 0 005 3 0 01 2 0 043 4 0 02 ala 1 lsd No

For the nuclear reaction A 8 Ax Ax 4 Y t 2 1600 yrs Z If initial activity was 107 dps how many a particles will be emitted per second after 4800 years Question Type Single Correct Type 1 25 x 106 s 1 2 2 5x 106 s 1 3 1 25 x 107 s 1

gas deco COCI g oses us CO g Cl g Blad V If one mole of He gas is added in the vessel at equilibrium at constant pressures then 000 a COCI increases b Moles of CO will increases c The reaction goes in forward direction d K 1 milom atni boyuboral nos munditions What would be the effect of increasing the volume of each of the following systems at equilibrium llw D d a 2CO g O g 2CO g 1919 b Ni s 4CO g c N O g Ni CO g erol onto 2NO g Bit mon by il 14 b Ka

Illustration 7 167 For the reactions X2Y and Z P Q occurring at two different pressure P and P respectively The ratio of the two pressure is 1 3 What will be the ratio of equilibrium constant if the degree of dissociation of X and Z are equal

In a hypothetical solid C atoms forming cubical closed packed lattice A atoms occupy all tetrahedral void and B atoms occupy all octahedral voids There is no distortion in ccp lattice Fraction of body diagonal not covered up by atoms is Question Type Multiple Correct Type 2 3 4 0 76 0 24 0 68 0 12

The production of ammonia gas NH3 can be achieved from the reaction of nitrogen gas N2 with hydrogen gas H2 N2 3H2 2NH3 The isothermal and isobaric irreversible reaction consisting of 75 mol H2 with its partial pressure of 9000 kPa and the balance air is carried out in a 30 0 dm3 batch reactor at 475 0 K initially From a prior study it is determined that the reaction is first order with respect to N2 and second order with respect to H2 Air consisted of 79 mol N2 and the balance 02 N2 must be used as the basis of calculations Given the reaction rate constant as 10 0 dm6 mol2 min at 500 0 K and 2 5 dm6 mol2 min at 300 0 K 1 Construct a stoichiometric table for the above reaction All values should be in function of conversion X only by evaluating numerically all other

If 8 g of a non electrolyte solute is dissolved in 114 g of n octane to reduce its vapour pressure to 80 the molar mass in g mol of the solute is Given that molar mass of n octane is 114 g mol NEET 2020 Phase 2 1 20 3 60 2 40 4 80

Which of the following has been arranged in order of decreasing freezing point Question Type Single Correct Type 0 05 M KNO3 0 04 M CaCl 1 0 140 M sugar 0 075 M CuSO4 2 3 4 0 04 M BaCl 0 140 M sucrose 0 075 M CuSO4 0 05 M KNO3 0 075 M CuSO4 0 140 M sucrose 0 40 M BaCl 0 05 M KNO3 0 075 M CuSO4 0 05 M NaNO3 0 140 M sucrose 0 04 M ROCL

3 The rate constant of a reaction is 1 5 107 s 1 at 50 C and 4 5 x 107 s 1 at 100 C What is the value of activation energy 1 2 2 103 J mol 1 3 2 2 104 J mol 1 2 2300 J mol 1 4 220 J mol 1

The Henry s law constant for CO dissolved in water is 1 67 108 Pa at 298 K Calculate the mole fraction of CO in 1 L of soda water when packed under 2 5 atm pressure at 298 K 1 atm 101325 Pa

The catalytic decomposition of N O by gold at 900 C and at an initia complete in 53 minutes and 73 complete in 100 minutes What is the order of the reaction ruti Calculate the velocity constant A 200 120 su Au B C How much of N O will decompose in 100 min at the same temperature but at initial pressure of to sux t 1w t n 19 600 mm has been measured at different

The osmotic pressure of urea solution at 10 C is 200 mm becomes 105 3 mm when it is diluted and temperature raised DO to 25 C The extent of dilution is 1 8 times 2 5 times 3 4 times 4 2 times

3 The resistance of a KCI aqueous solution is 10 Xx24592 If the electrodes in the cell are 4 cm apa and area having 7 cm2 each the mola conductance of the solution will be 1 233 3 23 32 2 2 33 4 0 233

When 1 0gm equivalent of each acid HA and HB are neutralized separately by NaOH the amount of heat released are 43kJ and 27 kJ respectively Which of the following is incorrect Question Type Single Correct Type 1 2 3 4 Both HA and HB are weak acids Ionisation constant of HA is greater than HB Enthalpy of ionisation of HB is greater than HA Enthalpy of ionisation of HA is greater than HR

Q73 Select the correct statement out of I II and III for zeroth order reaction I Quantity of the product formed is directly proportional to time II Larger the initial concentration of the reactant greater the half life period III If 50 reaction takes place in 100 minutes 75 reaction take place in 150 minutes doubt ang speed I only Band II only C II and III only D I II and III only Q 74 Identify the strongest base Q 73 an is Axy 2 K 1 V 300 2XV 7 Q 74 W T II aftame at fre gargara 3 50 III 100 Peso fam 1150 2 affe 1 A B 1 II C S4 II I D 1 II NH III

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 1 c 358 5 kJ mol 1 2006 b 269 9 kJ mol 1 d 508 9 kJ mol 1

ble can be prepared from K MnO as per the KMnO4 can be reaction 3MnO2 2H 0 2MnO4 MnO 40H The reaction can go to completion by removing OH ions by adding NEET 2013 1 KOH 3 SO 2 2 CO 4 HC

I mole of anhydrous X is added in 1 Kg water volume is finally I litre To this mixture small amount of Y is added such that it acts as Limiting reagent In each case Y reacts to give water soluble products Identify the correct option s List I X Y P KCN AgCN s S Q CuS Cone HNO R Hgly KI S CH COOH Ba OH s List II Effect of addition of Y on X water mixture 1 Freezing point decreases Osmotic pressure does not increases 2 3 Freezing point does not increases Vapour decreases A P 2 3 Q 1 3 R 1 4 S 3 4 pressure share 2 3 R 1 4S 3 4

1 Topic 1 First Law and Basie Fundamentals Thermodynamics of The correct option for free expansion of an ideal gas under adiabatic condition is a q 0 AT 0 and w 0 2020 b q 0 AT 0 and w 01 c q 0 AT 0 and w 0 d q 0 AT 0 and w 0 2 An ideal gas expands isothermally from 10 m to 102 m at 300 K against a constant pressure of 105 Nm 2 The work done on the gas is INEET Odisha 2019 b 270 kJ d 900 kJ Reversible expansion of an ideal gas under isothermal and adiabatic conditions are as shown in the figure NEET Odisha 2019 a 900 kJ c 900 J 4 APA VA TA B PVT C Pc Vc Tc AB Isothermal expansion AC Adiabatic expansion Which of the following options is not correct 9 a T TA b AS AS othermal nothermal c T TB d W W Under isothermal condition a gas at 300 K expands front 0 1 L to 0 25 L against a constant external pressure of 2 bar The work done by the gas is Given that 1 L bar 100 J 2019 a 30 J b 5 kJ c 25 J d 30 J Three moles of ar spontaneously into va be a Zero c 3 Joules 10 Which of the follow 1 q w 111 w a 1 and IV c I II and C 11 In a closed insula with a paddle to of the followin a AE W c AE 0 W When I mol volume temp If heat suppl statement is a q w b q AU c q v d AU 12

Starting from 2 propanol what are the appropriate sequence of steps that will lead to methyl propyl ether OH methyl propyl ether 1 NaOH 2 HBr 3 H SO4 heat 4 NaNH then CH3Br 1 NaOH 2 HBr ROOR 3 H SO4 heat 4 NaNH2 then CH3Br 1 H SO4 heat 2 HBr ROOR 3 NaOH 4 NaNH2 then CH3Br 1 H SO4 heat 2 HBr 3 NaOH 4 NaNH then CH3Br 1 NaOH 2 Hg OAc 2 CH3OH 3 NaBH4

vii L Ribose viii Lactose Tollen s reagent If X Y Z is number of mole of HIO consumed by 1 mole of sucrose 1 mo Y Z 1 of glucose 1 mole of fructose respectively Then value of is X HNO

1g of graphite is burnt in a bomb calorimeter in excess of oxygen at 298 K and 1 atmospheric pressure according to the equation C graphite O g CO g During the reaction temperature rises from 298 K to 299 K If the heat capacity of the bomb calorimeter is 20 7kJ K what is the enthalpy change for the above reaction at 298 K and 1 atm

5 Ethylene glycol is used as an antifreeze in a cold climate Mass of ethylene glycol which should be added to 4 kg of water to prevent it from freezing at 6 C will be K for water 1 86 K kg mol and molar mass of ethylene glycol 62 g mol 1 804 32 g 3 400 00 g 2 204 30 g 4 304 60 g AIEEE 2011

The K 25 C of sparingly soluble salt XY s is 3 56 x 10 5 mol L 3 and at 30 C the vapour pressure of its saturated solution in water is 31 78 mm of Hg Calculate the enthalpy change of the reaction XY s X aq 2Y aq Given Vapour pressure of pure water 31 82 mm of Hg

Illustration 6 72 A constant pressure calorimeter consists of an insulated beaker of mass 92 g made up of glass with heat capacity 0 75 J K g The beaker contains 100 mL of 1 M HCl at 22 6 C to which 100 mL of 1 M NaOH at 23 4 C is added The final temperature after the reaction is complete is 29 3 C What is AH per mole for this neutralization reaction Assume that the heat capacities of all solutions are equal that of same volumes of water

Two liquids A and B have vapour pressure of 0 600 bar and 0 2 bar respectively In an ideal solution of the two calculate the mole fraction of A at which the two liquids have equa partial pressures

i ker 1 0 25 DP BP 26 a 3b C 2a b 2x0 1671 0 25 3 0167 1 0 142 0 5 0 167 xample 7 44 One mole of N O g at 100 K is kept in a sed container at 1 0 atm pressure It is heated to 400 K here 30 by mass of N O g decomposes to NO 2 The sultant pressure will he

Q 73 Select the correct statement out of I II and III for zeroth order reaction I Quantity of the product formed is directly proportional to time II Larger the initial concentration of the reactant greater the half life period III If 50 reaction takes place in 100 minutes 75 reaction take place in 150 minutes doubt CA Igaly Band II only C II and III only D I II and III only ang sheed F V Q74 Identify the strongest base 2Y NH 2 300 Q 73 fer IK 1 II VE3ee 2 7 III 100 2 50 fa R 150 C 31 A S 1 B I C II D 1 II NH 74 1 II III III

d 4 92 A mixed solution of potassium hydroxide and sodium carbonate required 15 mL of an N 20 HCl solution when titrated with phenolphthalein as an indicator But the same amount of the solution when titrated with methyl orange as indicator required 25 mL of the same acid The amount of KOH 93

4 None of the above 3 1 mole Al C reacts with H O in a closed vessel at 27 C against atmospheric pressure Work done is 1 1800 cal 3 1800 cal 2 600 cal 4 zero

100 mL of 0 01 M KMnO oxidised 100 mL H O in acidic medium Volume of the same KMnO4 required in alkaline medium to oxidise 100 mL of the same H O will be MnO changes to Mn in acidic medium and to MnO in alkaline medium 2 2 02 HI 22 nM PE

6 If for a sucrose elevation in boiling point is 1 0 C then what will be the boiling point of NaCl solution for same molal concentration 3 3 0 C 1 1 0 C 2 2 0 C 7 Th 4 4 0 C 200

5 Which of the following statements is not correct for a nucleophile Re AIPMT 2015 1 Nucleophiles attack low e density sites 2 Nucleophiles are not electron seeking 3 Nucleophile is a Lewis acid 4 Ammonia is a nucleophile

y 6 The degree of dissociation a of a weak electrolyte A B is related to van t Hoff factor i by the expression 1 3 i 1 x y 1 x y 1 i 1 2 4 i 1 x y 1 x y 1 i 1

9 In the following given numbers how many are the magic numbers 5 1 16 2 8 20 50 113 126 141 148 300 314 1 4 2 7 3 5 E 4 9 1 950 711

Example 7 42 Following two equilibria are establ mixing two gases A and C i 3A g A g ii A g C g A C g 23 c K 1 6 atm P 020 If A and C are mixed in 2 1 molar ratio calculate the equilibrium partial pressures of A C A C and K for the reaction ii Given that the total pressure to be 1 4 atm and to ho 02 atm at equilibrium

6 Mole fraction of component A in vapour phase is X and mole fraction of component A in liquid mixture is X PA vapour pressure of pure A then the total vapour pressure of the liquid mixture is 2 1 PA 2 X PB X 3 PA XI X PB X2

You need a 55 alcohol solution On hand you have a 660 mL of a 65 alcohol mixture How much pure water will you need to add to obtain the desired solution You will need to obtain mL of pure water mL of the desired 55 solution

0 5 m solution of acetic acid Mw 60 in benzene Mw 78 boils at 80 80 C The normal boiling point of benzene is 80 10 C and Ava H 30 775 kJ mol Calculate the percent of association of acetic acid in benzene

6 Co NH3 6 3 6 4 A first order reaction has a specific reaction rate of 10 2 sec 1 How much time will it take f 20 g of the reactant to reduce to 5g log 4 0 6020 1 138 6 sec 2 346 5 sec 3 693 0 sec 4 238 6 sec

1 Two liquids X and Y form an ideal solution at 300 K vapor pressure of the solution containing 1 mol of X and 3 mol of Y is 550 mm Hg At the same temperature if 1 mol of Y is further added to this solution vapor pressure of the solution increases by 100 mm Hg Vapor pressure in mm Hg of X and Y in their pure states will be respectively 1 200 and 300 2 300 and 400 3 400 and 600 4 500 and 600

D 1 548 25 In fcc arrangement the distance between adjacent layers of close packing is 81 65 pm then the smalles possible radius of a foreign atom that can be placed in a void is A 50 00 pm B 35 35 pm D 20 25 pm C 11 25 pm 400 ml of aqueous Cuso colution in 26

If radius ratio r r is equal to 0 7 then coordination number of cation will be 1 2 4 6 8 Both 6 as well as 8 3

List I List II A AG 0 I K 1 B AG 0 II K 1 C AGO 0 III K 1 Choose the correct answer from the options given belov 1 A I B II C III 2 A II B I C III 3 A I B III C II 4 A II B III C I

If sodium sulphate is considered to be completely dissociated into cations and anions in aqueous solution the change in freezing point of water AT when 0 01 mole of sodium sulphate is dissolved in 1 kg of water is K 1 86 K kg mol

Example 7 42 Following two equilibria are established on mixing two gases A and C 02u i 3A g A g ii A g C g A C g K 1 6 atm P 0800 urfT P If A and C are mixed in 2 1 molar ratio calculate the equilibrium partial pressures of A C A C and K for the reaction ii Given that the total pressure to be 1 4 atm and partial pressure of A to be 0 atm at equilibrium

Illustration 7 153 K for the reaction N 0 2NO in chloroform at 291 K is 1 14 Calculate the free energy change of the reaction when the concentration of the two gases are 0 5 mol dm3 each at the same temperature GISIA R 0 082 L atm Kmot

0 When during electrolysis of a solution of AgNO3 9650 coulombs of charge pass through t electroplating bath the mass of silver deposited on the cathode will be 3 21 6 g 4 108 g 1 1 08 g 2 10 8 g