Physical Chemistry Questions

is m charge is and it is accelerated from rest through a potential difference of V volt The velocity acquired by electron will be Question Type Single Correct Type 1 2 C V eV m 7orn

Which of the following reactions can be used to prepare acetophenone A Reaction of benzene with acetyl chloride in presence of anhydrous AlCl3 B Dry distillation of a mixture of calcium benzoate and calcium acetate C Oxidation of ethyl benzene by vanadium peroxide D By the action of CH3 2Cd on benzoyl chloride followed by acid hydrolysis

The top surface of a 10 by 10 m horizontal plate is maintained at 25 C and exposed to room temperature at 28 C Estimate the heat transfer Abwm horizontal hooter in ploood in innt 150A DA

Q 15 O 29 5 10 O At 25 C the standard e m f of cell having reactions involving a two electron change is found to be 0 295 V The equilibrium constant of the reaction is 10t 4 1 10 0 00 35 6

During electrolysis of an aqueous solution of sodium sulphate 2 4 L of oxygen at STP was liberated at anode The volume of hydrogen at STP liberated at cathode would be Question Type Single Correct Type 1 1 2 L 2 2 4 L 3 2 6 L 401

convert Question Type Single Correct Type 1 Infusible impurities to fusible material

The stability of the following alkali metal chlorides follows the order Option A B C D LICI KCI NaCl CsCl CsCl KCI NaCl LICI NaCl KCI LICI CsCl KCI CSCI NaCl LiCl

A gaseous mixture was passed at the rate of 2 5L min through a solution of NaOH for a total of 1 hour The SO in the mixture was retained as sulphite ion SO g 2OH SO g H O l After acidification with HCl the sulphite was titrated with 5ml of 0 003M KIO 10 2H SO 2Cl250 IC 2H H O Calculate concentration of SO2 in ppm if density of gaseous mixture is 1 6 gm L

Volume of CO obtained at STP by the complete decompoisition of 9 85 g BaCO3 is At wt of Ba 137 1 2 24 lit 2 1 12 lit 3 0 84 lit 4 0 56 lit nd 3

Q 21 O O The molecular conductivity and equivalent conductivity are same for the solution of O O 4 1 M NaCl 1 M Ba NO 32 1 M La NO3 3 00 31 1M Th NO 3 4 O 000

Biological colloid is prevented from coagulating by which method A steric polymeric stabilisers only B electrostatic stabilisers only C D charged species bound to the surface only both steric polymeric and electrostatic stabilisers

6 When NO is cooled to room temperature some of it reacts to form a dimer N 04 2 2 through the reaction 2NO g N O4 9 2 In a reaction 15 2 g of NO is placed in a 10 0 L flask at high temperature and the flask is cooled to 25 C The total pressure is measured to be 0 500 atm Thus partial pressure of NO2 is found to be a 0 19 atmest b 0 31 atm c 0 10 atm d 0 40 atm

Q 20 moderate The depression in f p of 0 01 m aqueous solution of urea sodium chloride and sodium sulphate is in the ratio O 1 1 1 O 1 2 3 O 1 2 4 O 4 1 00 21 2 2 3

Freundlich adsorption isotherm equation Question Type Single Correct Type X 1 m k p1 n n 1 2 3 4 E x E m kp1 n 1 kp1 n 0 1 X kp1 n 0 1

2 AH of a reaction A B C is x kJ and forward reaction has activation energy y kJ The activation energy for the reverse reaction is 1 x y kJ 3 x y kJ 2 y x kJ X y 4 kJ Fincrone twice as fast as the rate constant of a second

Question Type Single Correct Type 1 2 3 a 3 2 P P P P V 0 2b 0 2RT a v 0 04V V b 0 02RT 0 04a 2 V V 0 2b 0 2RT 0 2a

The unit cell of an element of atomic mass 108 u and density 10 5 g cm 3 is a cube with edge length 409 pm Find the type of unit cell of the crystal Given Avogadro s constant 6 023 x 1023 mol Comptt Delhi 2012

Choose the correct statement about Henry s constant 1 KH in bar increases with increase in temperature generally II KH in bar decreases with increase in temperature generally III KH in bar is the characteristic constant of gas solvent system Question Type Single Correct Type 1 1 III 2 11 III 3 1 11

3 10 3 a gaseous reaction is given by the expression K A B If the volume of the reaction vessel is suddenly reduced to 1 4th of the initial volume the reaction rate relating to original rate will be 1 1 10 2 1 8 3 8 The rate expression for the reaction NH4CNONH CONH Can be derived from the mechanism 1 NH4CNONHANCO fast ii NH4NCONH3 HNCO fast iii NH3 HNCO K4NH CONH slow Which of the following statement are correct about rate expression 1 2 3 4 d urea k k NH NCO dt k d urea k k NH NCO dt k k d urea k NH NCO dt d dt urea k k The term 4 16 9 dc K K NH NCO k k4 rea 1 in a rate equation refers to the

Q 11 O 2 5 In acidic medium MnO4 is converted to Mn The quantity of electricity in faraday required to reduce 0 5 mole of MnO4 to Mn would be O 5 O 1 4 1 O 05 00 16 O 000

40 The equilibrium of which of the following reactions will not be disturbed by the addition of inert gas at constant volume AH g 1 g 2HI g C N O4 g 2NO g B PC1 g PCl g Cl g D N g O g 2NO g

During the adsorption of Krypton on activated charcoal at low temperature Question Type Single Correct Type 1 AH 0 and ASgas 0 2 AH 0 and ASgas 0 3 AH 0 and ASgas 0 4 AH 0 and ASgar 0

8 For He the electron is in orbit with energy equal to 3 4eV The azimuthal quantum number for that orbit is 2 and magnetic quantum number is 0 Then which of the following is are correct a The subshell is 4d b The number of angular nodes in it is 2 c The numbers of radial nodes in it is 3 d The nuclear charge experienced in n 4 is 2e less than that in n 1 where e is electi arge

7 For a sample of perfect gas when its pressure is changed isothermally from p to p the entropy change is given by a AS nR In Pf Pi c AS nRT In Pf Pi Pi In A Pf b AS nR In d AS RT In Pi Pf

Which of the graphs shown below does not represent the relationship between incident light and the electron ejected from metal surface A B K E of es 0 K E of es 0 Intensity of Light

For a reaction Ea 0 and A 3 2 x 104 s at 300K Then value of rate constant k at 310K would be Question Type Single Correct Type 1 6 4 x 104 S 1 2 3 2 x 104 S 1 3 3 2 x 108 S 1 A 32 x 105 1

The quantum numbers of most energetic electron in Ne atom when it is in first excited state is 1 2 1 0 1 2 2 3 1 1 1 2 3 3 0 0 1 2 4 3 1 0 1 2 4

Q 3 moderate 4 1 00 06 The standard reduction potential for Fe and Sn Sn electrodes Fe 0 30 V O are 0 44 V and 0 14 V respectively For 0 58 V the cell reaction Fe Sn Fe Sn the 2 2 standard e m f is Gabion willen

147 Amount of A FeSO4 NH4 2SO4 6H O molar mass 392 g mol must be dissolved and diluted to OS 250 mL to prepare an aqueous solution of density 1 00 g mL i e 1 00 ppm Fe2 by weight is de 1 a 3 50x 10 3 g c 7 00x 10 3 b 1 75 10 3 g d 0 35 x 10 3 o

Consider the following reaction 2A g 2B g C g For which the rate law is Rate K A and k 0 21 what is the concentration of C when t 40 seconds O 0 029 M O 0 036 M O 0 033 M L mol S Given the initial concentration of A is 0 150 M O 0 042 M hh

A cylinder of gas supplied by Bharat Petroleum is assumed to contain 14 kg of butane If a normal family requires 20 000 kJ of energy per day for cooking butane gas in the cylinder last for days AHc of C4H10 2658 kJ per mol Question Type Single Correct Type 1 15 2 20 3 50

Among the following the INCORRECT statement about colloids is The range of diameters of A colloidal particles is between 1 and 100 nm B The osmotic pressure of a colloidal solution is of higher order than the true solution at the same concentration C They can scatter light D They are larger than small molecules and have high molar mass

A solid XY kept in an evacuated sealed container undergoes decomposition to form a mixture of gases X and Y at temperature T The equilibrium pressure is 10 bar in this vessel Kp for this reaction is A B 5 10 25

Identify the incorrect statement among the following a Van der Waal s constant a is a measure of intermolecular force of attraction between the molecule b Intermolecular force of attraction increases with the increase in pressure c Van der Waal s constant a becomes negligible at high pressure d None of these

A metal oxide is reduced by heating it in a steam of hydrogen It is found that after complete reduction 3 15 gm of the oxide yields 1 05 gm of the metal We may conclude that 1 Atomic weight of the metal is 4 3 Equivalent weight of the metal is 4 2 Equivalent weight of the metal is 8 4 Atomic weight of the metal is 8 ARLESTWENDO SAD

1 The enthalpy of fusion of water is 1 435 kcal mol The molar entropy change for the melting of ice at 0 C is a 10 52 cal mol K c 5 260 cal mol K b 21 04 cal mol K d 0 526 cal mol K

Consider the following statements Matter consists of indivisible atoms p All the atoms of a given elements have identical properties including identical mass Atoms of different elements differ in mass C d Compounds are formed when atoms of different elements combine in a fixed ratio Atoms can neither be created nor destroyed in a chemical reaction e The correct statements are A a b c are correct statements B c d e are correct statements C a c e are correct statements 11 oro correct statements

The concentration of hydroxyl ion in a solution left after mixing 100 mL of 0 1 M MgCl2 and 100 mL of 0 2 M NaOH Ksp of Mg OH 1 2 10 is 1 2 8 10 3 x 2 2 2 8 x 107 3 2 8 x 10 4 4 2 8 x 10 5

If 8g of a non electrolyte solute is dissolved in114 g of n octane to reduce its vapour pressure to 80 the molar mass in gmol of the solute is Given that molar mass of n octane is 114 gmol 40 CORRECT ANSWER 60

Electrolysis can be used to determine atomic masses In a solution a current of 0 550 A deposits 0 55 g of a certain metal in 100 minutes Calculate the atomic mass of the metal if eq Wt molar wt 3 Question Type Single Correct Type 1 100 2 45 0

C 0 25 Two liquids of equal masses one at 20 C and the other at 40 C are mixed together The temperature of the mixture is 32 C The ratio of their specific heats is A 3 2 C 1 3 B 1 1 D 2 3 11 constant

If a person in an elevator accelerating upwards with an acceleration of 2ms tosses a coin vertically upwards with a speed of 20ms then after how much time will the coin fall back in to his hand g 10ms A 5 55 S C 25 5 S IT 1 B 1 55S D 3 33 S if truo on nore

Q 22 moderate O 1 In a 0 2 molal aqueous solution of a weak acid H X the degree of ionization is 0 3 00 30 Taking K for water as 1 85 the freezing point of the solution will be nearest to O 360 0 260 C

For a reaction 1 Ag O s 2Ag s O g 2 AH AS and T are 40 63 kJ mol 108 8 J K mol 373 4 K respectively Predict the feasibility of the reactio a feasible b non feasible

Question 4 3 marks Three ideal gases are mixed in a 3 5 L vessel The vessel is connected by a valve to a 5 0 L chamber This second chamber contains no gas at all it is a vacuum The three gases in the 3 5 L vessel helium neon and argon have the following partial pressures 17 0 kPa 22 0 kPa and 32 0 kPa What is the total pressure in the two chamber system after the valve is opened

Strontium chloride and sodium fluoride react to form strontium fluoride and sodium chloride according to the reaction shown SrCl aq 2 NaF aq SrF s 2 NaCl aq What volume of a 0 210 M NaF solution is required to react completely with 275 ml of a 0 200 M SrCl solution volume How many moles of SrF are formed from this reaction m mo

Identify the correct statement from the following The order of hydration enthalpies of alkaline earth cations 2 2 Be2 Mg2 Ca Sr Ba Lithium and Magnesium show some similarities in their physical properties as they are diagonally placed in periodic table CORRECT ANSWER Lithium is softer among all alkali metals Lithium chloride is deliquescent and crystallizes as a hydrate LiCI H O

Determine which solution in each pair is more acidic A 0 0100 M in HCl and 0 0100 M in KOH B 0 0100 M in HF and 0 0100 M in KBr C 0 0100 M in NH Cl and 0 0100 M in CH NH Br D 0 100 M in NaCN and 0 100 M in CaCl

Four containers of 2L capacity contains dinitrogen as described below Which one contains maximum num of molecules under similar conditions 1 2 5 gm molecules of N 3 3 01 x 1024 N atoms 2 4 gm atom of nitrogen 4 84 gm of dinitrogen

1 mol each of H and 12 are heated in a closed vessel till equilibrium is obtained If 40 of 12 is converted to HI the value of Kc at the same temperature will be H g 1 g 2HI g 2 1 1 8 1 2 3 2