Physical Chemistry Questions

Is a HF Stue b HCl 2 20 c HBr EVS bases d HI s to g Of At what pressure a quantity of gas will occupy a volume of 60 mL if it occupies a volur 100 mL at a pressure of 720 mm while temperature is constant HETS 8 700mm 900mm 100

generates photoelectrons of velocity 6x105 ms from it Mass of electron 9 10 kg Velocity of light 3 10ms Planck s constant 6 626 10 34 Js Charge of electron 1 6 10 19 JeV a 0 9 eV b 3 1 eV c 2 1 eV d 4 0 eV Main Jan 12 2019 1

Total number of structural unsaturated 3 alcohols possible with molecular formula C6H12O is aga Cat20ger foxat en s Enter your answer Type your answer here

0 PI Which of the following statement is correct i If A B are same gases then T2 T ii If T T then A g may be SO2 g B g may be CH4 g iii If B C are same gases then T3 T2 iv If T T T3 then A g may be CH4 B g may be SO2 C g may be SO3 g O i ii iii only Oi ii iv only O All are correct T CT3 ii iii only

32 60 hr mit Select the correct statements among following Nearest neighbour distance in NaCl 2 2 Nearest neighbour distance in CaF a 4 3 Nearest neighbour distance in Na O a 3 NIET Nearest neighbour distance in CsCl a

25 A 0 96 g sample of Fe O3 solid of 50 purity is dissolved in acid and completely reduced by heating the solution with zinc dust The resultant solution is cooled and made upto 100 0 mL An aliquot of 25 0 mL of this solution requires 30 mL of 0 01 M solution of an for titration Calculate the number of moles of electrons taken up by 1 mol of oxidising agent in the reaction of the above titration noxidising agent m

An amount of 1 mole of a non volatile solid is dissolved in 200 moles of water The solution is cooled to a temperature T K lower than the freezing point of solution to cause ice formation After removal of ice the remaining solution is heated to 373 K where the vapour pressure of solution is observed to be 740 mm Hg Select correct information Kf of water 2 K m 0 C 2 934 Kg of ice is formed at T K TK 273 2000 37 x 18 K Freezing point of the original solution is 10 18 C 1 Relative lowering of vapour pressure of the final solution is 38 4

B For a reaction scheme A B2C if the rate formation of B is set to be zero then the concentration of A given by 2019 Main 8 Apri a k k A c k k 4 1 d k k A b A

a 6 90 When a 20 mL of 0 08 M weak base BOH is titrated with 0 08 M HCl the pH of the solution at the end point is 5 What will be the pOH if 10 mL of 0 04 M NaOH is added to the resulting solution 10 log 0 30 and log 3 0 48

gm H O A is mixed with 70 gm of H O B in a rigid adiabatic vessel The initial temperature of A B was 46 70 C Fir ange in enthalpy of water H O A in calories specific heat of water 1 cal gm c

An ideal mixture of liquids A and B with 2 moles of A and 2 moles of B has a total vapour pressure of 1 atm at a certain temperature Another mixture with 1 mole of A and 3 moles of B has a vapour pressure greater than I atm But if 4 moles of C are added to the second mixture the vapour pressure comes down to 1 atm Vapour pressure of C P 0 8 atm Calculate the vapour pressures of pure A and pure B

The resistance of a conductivity cell is 1000 ohm when 0 1 M HA is present in the cell The pH of solution in the cell at 25 degree C is 2 Cell constant and Ka of HA are respectively Given delta M not of HCl NaCl and NaA are 420 126 and 106 S cm2 mol 1 respectively where delta M not is limiting molar conductivity

The Lassaigne s extract is boiled with conc HNO3 while testing for the halogens By doing so it B decomposes Na S and NaCN if formed helps in the precipitation of AgCl increases the solubility product of AgCl increases the concentration of NO ions

For the decomposition of dinitrogen pentoxide at 200 C N 0 g N O g O g if the initial pressure is 114 mm and after 25 minutes of reaction the total pressure of gaseous mixture is 133 mm calculate the average rate of reaction in a atmosphere min and b mol L

5 What mass of non volatile solute urea needs to be dissolved in 150 g of water in order to decrease the vapour pressure of water by 35 What will be the molality of solution 1 23 88 3 25 47 2 31 12 4 29 92

The reaction below has an equilibrium constant of K 4 253 x 10 What is the concentration of Cleq at equilibrium when the initial concentrations are A 1 00 M B 2 00 M and C 0 00M A B 2C

Definition of a mixture is anything that can b e seperated by a physical process accordin g to the video Q1 Is there anything that is made up of two or more substances but they cannot be sep erated by a physical process and so are clas sified as pure substances Q2 Is there anything which can be seperate d by a physical process but is classified as a pure substance

The work function for Ag metal is 7 5 x 10 19 J Ag metal is being exposed to the light of frequency 1220 Which is are correct statements 1 Threshold frequency of metal is 1 135 1015 s 1 2 Threshold frequency of metal is 8 33 1015 S 1 3 Stopping potential is 5 46 volt 4 If light of wavelength 3600 is used then phot

Choose the correct order of the following O Na g Mg g Al g lonic radius Mg aq Sr aq Ba aq Hydrated radius order Mg aq Sr aq Ba aq lonic mobility order

0 Which of the given aqueous solution has the maximum boiling point K of H O 0 52 mol kg T H O 373 K 1 6 urea solution by weight of solution 2 18 glucose solution by weight of solution 3 34 2 sucrose solution by weight of solution 4 All have equal boiling points

What will be compound C and F respectively Cl hv Alcoholic CH3 CH CH3 B KOH F Na dry ether E Br A Mono chlorinated HBr 2 eq H O D O CH CH CH and O CH CH CH and Br Na dry ether O CH3 CH CH Br and CH3 CH CH Br and NBS N bromo succinamide C Mono brominated Br Br

1 The molality of a urea solution in which 0 0200 g of urea NH CONH is added to 0 400 dm of water at STP is 1 0 555 mol kg 1 3 8 33 104 mol kg 2 5 55 104 mol kg 1 4 33 3 mol kg

At 298 K the standard Gibbs energy of formation of H O is 256 5 kJ mol while standard Gibbs energy of its ionisation to H OH is 80 kJ mol What will be emf at 298 K of the cell volts H g 1 bar H IM OH IM O g 1 bar

Chlorine atom has two naturally occurring isotopes 35Cl and 37CI with respective molar abundance of 75 and 25 Which of the following is are correct for Cl2 molecules A There are three types of Cl2 molecules on the basis of molecular mass B Average molar mass of Cl2 is 72 g mol C In a Cl2 sample molar abundance of the heaviest possible Cl molecule is 6 25 D In a Cl sample molar abundance of the 35C137CI molecule is 18 75 25 3 75 Y H 1 A re B C 72 g mol 1 C C1 C 6 25 1 D Cl 3513718 75 1 5

3 A current of dry air is passed through a bulb containing 5 g of a solute in 100 g of water and then through water alone The losses in weight of the solution and pure water were respectively 0 78 g and 0 02 g Calculate relative lowering of vapour pressure 1 2 04 3 0 03 2 1 05 4 0 09

In chromium chloride CrC13 Cl ions have cubic close packed arrangement and Cr ions are present in the octahedral holes The fraction of the total number of holes occupied is 4 1 12 1 1 3 2 1 6 3 1 9

DA BI Can auto o que Each question has FOUR options A B C and D ONLY ONE of these four options is correct For each question marks will be awarded in one of the following categories Full Marks 4 If ONLY the correct option is chosen Zero Marks 0 If none of the options is chosen i e the question is unanswered Negative Marks 2 In all other cases Column l 1 CH 11 Fe 2 III V 3 IV Mn 2 1 ii Column II Total number of unpaired P Spin only magnetic electrons are 2 moment is 35 BM Total number of electron related to f 2 are 6 iii Total spin 2 iv Total number of electrons related to n 5 are 5 H 11 Column III 4 Q Total number of electrons having n 5 are 2 R Total number of electrons having n f 5 are 6 S Spin only magnetic moment is 24 BM DIGH III

2 Molar solubility of helium nitrogen and oxygen are plotted against partial pressure of the gas at constant temperature Henry s law constant for these gases will lie in the following sequence 1 0 N He 3 O N He Solubility 0 Partial Pressure 2 O N He 4 ON H N He

N 46 48 49 50 The Enthalpy of formation of H SO4 at 298K will be Given S 02 SO SO2 1 2 0 SO3 SO3 H O H SO4 H 1 2 02 H O Question Type Single Correct Type 1 810 KJ 3 1 2 710 KJ 4 51 52 53 54 55 56 680 KJ English Review Q 510 KJ AH 300 KJ AH 100 KJ AH 10 KJ AH 280 KJ

Structure of Atom 231 A light of frequency 1016 Hz is irradiated on a metal surface with threshold frequency equal to 5 1015 Hz What would be the maximum kinetic energy of photoelectrons emitted 1 3 313x10 15 J 2 3 313x10 18 J 3 1 02 1016J 4 4 316x10 18 J

23 A mixture of two immiscible liquids nitrobenzene and water boiling at 99 C has a partial pressure of water 733 mm and of nitrobenzene 27 mm The ratio of mass of water and nitrobenzene in mixture is

A certain hydrate has the formula MgSO4 xH O A quantity of 54 2 g of the compound is heated in an oven to drive off the water If the steam generated exerts a pressure of 24 8 atm in a 2 0 L container at 120 C calculate x bacose a bre

The molar conductivity of 0 00241 M acetic acid is 32 87 S cm mol If the limiting molar conductivity at 298 K is 390 5 S cm mol what is the dissociation constant mol L 1 1 86 x 10 5 X2 5 36 x 10 5 X3 5 36 x 10 4 X4 1 86 10 4 I

B A current of dry air is passed through a bulb containing 5 g of a solute in 100 g of water and then through water alone The losses in weight of the solution and pure water were respectively 0 78 g and 0 02 g Calculate relative lowering of vapour pressure 1 2 04 3 0 03 2 1 05 4 0 09

When sodium chloride is dissolved in water energy is absorbed potential energy of the product Na aq Cl aq have higher potential energy than NaCl s H 0 1 Which statement is consistent with the very high solubility of NaCl in water The presence of Na and Cl restrict the number of possible configurations that water can adopt Na and Cl are more energetically stable in the aqueous solution Water interacts with Na and Cl ions more strongly than with other water molecules Na and Cl and water also adopt more configurations when mixed together

A hydrogen atom and a He atom are approaching each other with speed v 2v respectively The minimum kinetic energy that He atom must have so that both the atom can excite to 1st excited state will be A 20 4 eV B 113 33 eV C 81 6 eV D 102JeV

Nitrogen and Carbon dioxide gases are heated from 800K to 1300K at a constant pressure of 1 bar For heating of the two gases which process will be more spontaneous Note Comment using proper calculation only Answer without calculation will not be justified You may use required parameters constant for solving from any external source Please mention the data equation used for your calculation

Tue as 1st excitation energy of H atoms A hydrogen like atom in ground state absorbs n photons having the same energy and it emits exactly photons when electronic transition takes place Then the energy of the absorbed photon may be B 40 8 eV C 48 4 eV A 91 8 eV D 54 4 eV

3 Solute A is a ternary electrolyte and solute B is non electrolyte If 0 1 M solution of solute B produces an osmotic pressure of 2P then 0 05 M solution of A at the same temperature will produce an osmotic pressure equal to 1 P 3 2P 2 1 5P 4 3P

55 Phenol associates in benzene to a certain extent to form a dimmer A solution containing 20 x 10 kg phenol in 1 kg of benzene has its freezing point depressed by 0 69 K The fraction of phenol is mm that has dimerised K for benzene 5 12 kg mol K

b According to the Collision theory for a reaction to occur between molecules there are three requirements that must met by molecules Mention these three requirements 3 The rate constant for a certain first order reaction is 0 40 min 1 i Calculate the initial rate in mol L min if the initial concentration of the compound involved is 0 50mol L 3

53 If m gram of a metal A displaces m2 gram of another metal B from its salt solution and if the equivalent weights are E and E respectively then the equivalent weight of A can be expressed by A E C E m xE m m x m E B E 1xE m D E m x m E

The preparation of SO3 g by reaction SO g O g SO3 g is an exothermic reaction If the preparation follows the following temperature pressur relationship for its yield then for temperatures T T2 and T3 The correct option is PEA 40 20 10 Pressure atm O T3 T T1 O T1 T T3 O T T T3 O Nothing could be predicted about temperature through given information Marks 4 1

c A piston expands against latm of pressure fro absorbed Consider a mixture of air and gasoline vapour in a cylinder with a piston The original volume is 40 cm If combustion of this mixture releases 950J of energy to what volume will the gas in L expands against a constant pressure of 5 bar if all the energy of combustion is converted into work to push back piston CIL bes a volume of 876 L at 0 08 C and 1 atm pressure At constant balloon to expand to a volume

58 For following two gaseous reactions SO g O g SO3 g K 2SO3 g 2SO g O g K If K 4 x 10 3 then K will be A 8 x 10 3 C 6 25 x 108 B 6 25 x 104 D 8 x 104

2 17 A 0 518 g sample of lime stone is dissolved in HCl and then the calcium is precipitated as CaC O4 After filtering and washing the precipitate it requires 40 0 mL of 0 250 N KMnO4 solution acidified with H SO4 to titrate it as MnO4 H CrO2 Mn CO 2H O 2 4 2 The percentage of CaO in the sample is a 54 0 c 42 b 27 1 d 84

Ka for the reaction Fe3 aq H O 1 Fe OH 2 aq H3O aq is 6 5x 10 What is the max pH value which could be used so that at least 80 of the total iron III in a dilute solution exists as Fe3

9 How many grams of sucrose M wt 342 should be dissolved in 100 g water in order to produce a solution with a 105 0 C difference between the boiling point and the freezing temperatures K 1 86 C m K 0 51 C m 1 34 2 g 3 342 g 2 72 g 4 460 g

12 The cryoscopic constant for acetic acid is 3 6 K kg mol A solution of 1 g of a hydrocarbon in 100 g of acetic acid freezes at 16 14 C instead of the usual 16 60 C The hydrocarbon contains 92 3 carbon What is the molecular formula 1 CH 3 CgH18 2 C6H12 4 C10H6

An electron jumps to higher excited state of a orbital which is non directional and have 4 radial node then shell with which electron belong Magnetic momentum of an ion M3 is 35 BM Then number of electron in d orbital of M element will be A sample contain only hydrogen atoms and in all atom electron are present at 4th excited state How many minimum number of atoms required if total seven lines are observed in emmission spectrum