Physical Chemistry Questions

390 7 and for mol The deg solution is a 13 3 18 The equivalent conductance of monobasic acid at infinite dilution is 348 ohm cm eq If the resistivity of the 27 The position solution containing 15 g acid mol wt 49 in 1 litre is 18 5 ohm cm What is the degree of dissociation of acid series in decre Mg Al Zr b 40 2 c 60 4 d 50 7 spoo a 45 9 9 Calculate the emf in V of th

The Ca and F are located in CaF crystal respectively at face centred cubic lattice points and in 1 Tetrahedral voids

Describe the effect of the following factor whether the increase decrease or has no effect on the actual yield of CaCO3 s in the limiting reactant experiment Using a coarse filter paper instead of one with fine porosity Select one Increase Decrease Has no effect

Which of the following structures is correctly drawn according to fundamental idea of VSEPR theory a b c d H FOF F F CL 0 greater than 109 28 F Cl Cl S e Si Cl 0 less than 90 F 0 90 F 0 90

Fused quartz transmits 90 percent of the incident thermal radiation between 0 2 and 4 um Suppose a certain heat source is viewed through a quartz window What heat flux in watts will be transmitted through the material from blackbody radiation sources at a 800 C b 550 C c 250 C and d 70 C

15 A solution contains 10 40M Cu 1 M Zn as the only will be reduced at cathode first Given E Cu 0 34V E a Cu2 b Zn c Both are reduced at same time d None of ion is reduced 6 The standard reduction potential Zn 0 76V Zn Zn C 24 7

Consider the equation Z PV nRT which of the following statements is correct a When Z 1 real gases are easier to compress than the ideal gas b When Z 1 real gases get compressed easily c When Z 1 real gases are difficult to compress d When Z 1 real gases are difficult to compress

Match List I with List ll and select the correct answer using codes given below the lists List II Magnetic moment B M List I Metal ions 1 Cr3 2 Fe2 3 Ni2 4 Mn A 35 B 30 C 24 D 15 E 8 1 1 B 2 C 3 E 4 D 3 1 D 2 C 3 E 4 A Which is an incorrect statement 2 1 B 2 C 3 E 4 A 4 1 D 2 E 3 C 4 A AAJ KA TOPPER

Consider the following reactions 2 i CO3 H O ii CO H 0 H CO3 iii NH3 H 0 NH OH iv HCl H O Cl H O HCO3 OH Which of the pairs of reactions proves that water i amphoteric in character a i and ii c iii and iv b ii and iii d i and iii

H O is prepared in the laboratory when 1 MnO2 is added to dilute cold H SO4 2 BaO is added to CO bubbling through cold water 3 PbO2 is added to an acidified solution of KMnO4 4 Na O is added to boiling water At certain Hill station pure water boils at 99 72 C If Kh for water is 0 513 Ckgmol

The yellow colour of ZnO and conducting nature produced in heating is due to 1 Metal excess defects due to interstitial cation 2 Extra positive ions present in an interstitial site 3 Interstitial electrons 4 All of the above

What would be the equivalent conductivity of a cell in which 0 5 N salt solution offers a resistance of 40 ohm whose electrodes are 2 cm apart and 5 cm in area 1 10 ohm cm eq 2 3 30 ohm cm ea 4 20 ohm cm eq 25 ohm cm eg ea

4 Among the following colloids the num ber of colloids having negatively charged colloidal particles is Soap solution of sodium palmitate sol of AgCl obtained on dissolving excess AgNO into KCl solution gold sol Fe OH sol silicic acid sol Basic dye Acidic dye metal sulphide sol sol of AgCl obtained by dissolving excess KC1 in AgNO solution ANSWER

In a hexagonal close packed structure which is ABAB type of packing select the correct statements Three fold axis of symmetry is present Six fold axis of symmetry is present All the octahedral voids are present entirely inside the unit cell and are not shared between adjacent unit cells All the tetrahedral voids are present entirely inside the unit cell and are not shared between adjacent unit cells

The rate constant k for a certain reaction is measured at two different temperatures temperature 275 0 C E 371 0 C Assuming the rate constant obeys the Arrhenius equation calculate the activation energy E for this react Round your answer to 2 significant digits k 2 2 10 4 8 10 kJ x10

101 Enthalpy of CH 02CH OH is negative If enthalpies of combustion of CH4 and CH3OH are x and y respectively then which of the following relations is correct a x y c x y 4 1 b x y d x p AMIL Med 11

How much will the reduction potential of a hydrogen electrode change when its solution initially at pH 0 is neutralized to pH 7 1 Increase by 0 059 V 2 Decrease by 0 059 V 3 Increase by 0 41 V 4 Decrease by 0 41 V

42 For the cell Ni Ni 0 1 M Au 1 0 M Au the value of emf will be if E for Ni2 Ni is 0 25 V E for Au Au is 1 50 V a 1 25V c 1 78 V If bud b 1 75 V d 4 0 V

A substance when dissolved in water at 10 M concentration absorbs 10 percent of an incident radiation in a path of 1 cm length What should be the concentration of the solution in order to absorb 90 of the incident radiation

2C1 0 g 2C1 g 50 g At a certain temperature it obeys this rate law rate 0 699 M CLOS Suppose a vessel contains Cl O at a concentration of 1 41 M Calculate the concentration of Cl O in the vessel 3 60 seconds later You may assum reaction is important Round your answer to 2 significant digits

ILLUSTRATION 8 1 If the density of methanol is 0 793 g mL what is its volume needed for making 2 5 L of its 0 25 M solution Solution We know M WBX 1000 MB XV Given M 0 25 mB 32 V 2500 mL 0 25 We know WB X1000 32 2500 Mass Volume x Density 20 Volume 0 793 Volume 25 22 mL or we 20 g ILLUSTRATION 8 2 Molarity of H SO4 is 0 8 and its density is 1 06 g mL What will be its concentration in terms of molality and mole fraction Solution Mass of H SO4 dissolved in 1 liter wg Mass of 1 liter solution 1000 x 1 06 1060 g Mass of solvent wA 1060 78 4 981 6 g WB X1000 78 4 1000 We know m 0 815 MB X WA 98 981 6 H Mole fraction of solute XB 0 8 nB NA NB 981 6 18 0 8 0 8 54 53 0 8 i 0 8 98 78 4 g 0 014

3 4 5 The number of moles of iron in a mixture of 144 gms FeO and 320 gms of Fe O3 will be The number of moles of neutrons found in 2 gms of Oxygen atoms will be If from a sample of 160 gms SO 6 023 x 1023 molecules are removed followed by removing 22 41 gas at STP then the mass of the remaining gas will be

The air is a mixture of a number of gases The major components are oxygen and nitrogen with approximate proportion of 20 is to 79 by volume at 298 K The water is in equilibrium with air at a pressure of 10 atm At 298 K if the Henry s law constants for oxygen and nitrogen at 298 K are 3 30 x 107 mm and 6 51 x 107 mm respectively calculate the composition of these gases in water

One mole of magnesium in the vapour state absorbed 1200 kJ mol of energy If the first and second ionization energies of Mg are 750 and 1450 kJ mol 1 respectively the final composition of the mixture is 1 86 Mg 14 Mg 2 36 Mg 64 Mg2 3 69 Mg 31 Mg2 4 31 Mg 69 Mg2

An aqueous solutions containing IM each of Au Cu Ag Li is being electrolyzed by using inert electrodes The value of standard potentials are E Ag Ag 0 80V Ecuc 0 34V E ALAL 1 50V EL 3 03V With increasing voltage the sequence of deposition of metals on the cathode will be 1 Li Cu Ag Au 2 Au Ag Cu 2 Cu Ag Au 4 Au Ag Cu Li

O H O KMnO4 H SO4 MnSO4 H O O2 K SO4 which is correct statement Number of gm equivalent of H O2 and KMnO4 reacts in the ratio of 5 2 Number of moles of MnSO4 and O2 produced in the ratio of 5 2 Equivalent mass of H SO4 is 29 4 100 ml 2 27 V H O2 reacts completely with 160 ml 0 5M KMnO4 in given reaction

AHO Latomisation C H g 2810 kJ mol AH C H g 25kJ mol AH H H 430kJ mol E Suppose Bond enthalpy of same bond in diffrent molecule will be equal Column 1 Column 2 Column 3 AHO AU A B Enthalpy of hydrogenation of C H4 g Enthalpy of formation of C H g C H6 g AHO C4H10 9 D C H4 g at very low temperature atomisation C H4 g 2255 kJ mol AHO will be positive Q AHO 225 11 P 1 Enthalpy of hydrogenation of C CH g R E of C H g is 150 R AH 125 III AS 0 kJ mol AHO AU S AHO 100 IV AGO 0

0 A 0 60 g sample consisting of only CaC O4 and MgC O4 is heated at 500 C converting the two salts of CaCO3 and MgCO3 The sample then weighs 0 465 g If the sample had been heated to 900 C where the products are CaO and MgO what would the mixtures of oxides have weighed A 0 12 g C 0 252 g B 0 21 g D 0 3 g

1 I IV 2 I II and IV 3 11 111 The reaction with incorrect major product is 47 H SO4 HC CH CH CHO 1 Ag 0 2 Me2 CHC1 Me CHOH BF3 C6H5OH CH N C6H5OCH3 3 4 CH CBr CBr CH3 2Zn CH3C CCH3 EtOH 4 All are correct

For the following reaction The thermodynamic parameters are Parametes AH kJ mol 2H g O g 2H 0 1 ASO j mol H O 1 285 9 70 H g 0 130 6 O g 0 205 Calculate at T 298K a Heat released by direct combustion b Maximum electrical work can be performed c Heat released in fuel cell during electrical work

There is no d d transition in Cu but Cu20 is coloured due to 1 The presence of unpaired electron 2 The presence of coloured 0 ion 3 Charge transfer from oxygen to metal

In the oxymercuration demercuration of the following compound CH I H C CH CH CH CH CH OH CH COO HS NaBH The major product is expected to be 1 2 3 H C HO D H C H C H C H C 4 H C CH CH

Consider the following statements 1 An increase in pressure caused by decrease in volume at equilibrium results in increase in molar concentration of each gaseous substance involved II An increase in pressure caused by decrease in volume at equilibrium results in increase in no of moles of each gaseous substance involved III For the reaction A s B g C g at constant temperature total pressure at equilibrium of B g C g is not affected by changing the volume of container IV H O l H O g on temperature increase K of this reaction is increased Tick the correct statement s A 1 B II C III D IV

a 26 80 Hours c 82 45 Hours Zn 65 b 41 23 Hours d 53 61 Hours 4 Electrochemical equivalent of a substance is 0 0006735 g C Its equivalent weight is a 25 d 65 c 40 d 27 5 During the electrolysis of Acidulated water th hydrogen nhtained in 12

32 Which of the following curves assures that ther obtained by carbon reduction is in the vapour state a AG AG b AG c 1 C CO AG C d T C CO T M MO T M MO C CO CO M M MO MO C

The equilibrium constant for the reaction H g S g H S g is 18 5 at 925 and 9 25 at 1000 respectively What is the enthalpy of the reaction 1 142 16 kJ mole 2 71 08 kJ mole 3 35 54 kJ mole 4 none of these

All the above statements are correct The correct order of the bond dissociation energies of various C H bonds present in the compound is 1 a B y 0 2 3 a 0 B Y Calculate the number of oxygen atoms required to combine with 7g of N to form N O when 80 2 a y 0 B 4 B a 0

4 H Se because of lower molecular weight Among KO AIO BaO and NO unpaired electron is present in 1 NO BaO 2 KO and AIO 3 KO only 4 BaO only An organic molecule necessarily shows optical activity if it

24 To a 25 mL H O2 solution excess of acidified solution of potassium iodide was added The iodine liberated required 20 mL of 0 3 N sodium thiosulphate solution Calculate the volume strength of H O2 solution Express your answer in millilitre

6 Which of the following adsorption isotherms shows the adsorption of a gas by a solid involving multi adsorption layer P denotes saturation pressure P a C x m x m P P P S b d x m x m P P P P

How many moles of Ca3 PO4 2 will contain 0 4 mol oxygen atom Question Type Single Correct Type 1 2 3 4 0 05 mol 0 4 mol 8 mol 4 mol

In a hypothetical solid C atoms from CCP lattice with A atoms occupying all the tetrahed voids and B atoms occupying all the octahedral voids A and B atoms are of the appropri size such that there is no distortion in the CCP lattice Now if a plane is cut as shown th the cross section of the plane would not be like A CBX C B B B B CCP unit cell B B B 00 Plane D OOO B COC

a P c R 37 Resistance of 0 2 M solution of an electrolyte is 50 2 The specific conductance of the solution is 1 4 Sm is 280 2 The molar conductivity of 0 5 M solution of the The resistance of 0 5 M solution of the same electrolyte 2 electrolyte in S m mol is a 5x10 4 c 5x103 b 5x10 3 d 5 10

Suppose above Fuel cell 25 KOH solution was used as electrolyte For it the anode half reduction potential is 0 83V and cathode half reduction potential is 0 40V What is the EMF of cell If the Fuel cell produces 10 mol of H O how long it can support a 100W electric bulb

7 Two monobasic weak acids have the same concentration of H ions What is the relationship between dissociation constant and dilution 1 Ka V Ka V 2 Ka V Ka V 4 Ka V Ka V 1 3 Ka V Ka V

For melting snow from sidewalks and roads the concept of depression in freezing point is applied Consider the solutes glucose NaCl and MgCl2 If these substances have the same cost per gram the most efficient solute would be assume electrolytic salts to be 100 ionised and M m Glucose NaCl MgCl Cannot be commented

aq Cuais unstable in solution and undergoes simultaneous oxidation and reduction according to the reaction 2000 2Cu aq Cu aq Cu s choose correct E for above reaction if E Cu2 Cu 0 34 V and E Cu Cut 0 15 V a 0 38 V c 0 38 V b 0 49 V d 0 19 V

Pb NO3 2 aq Na2S aq PbS s 2 NaNO3 aq When a 50 0 mL sample of 0 20 M Pb NO3 2 aq and a 50 0 mL sample of 0 20 M Na2S aq are mixed in a calorimeter a reaction occurs according to the equation above If the temperature of the mixture increases from 23 0 C to 26 0 C what is the experimental value of AH ran for the reaction Assume that the mixture has a total mass of 100 g and a specific heat of 4 2 J g C

CrCl 6H O exists in different isomeric forms which show different colours like violet and green This is due to a Ionisation isomerism b Coordination isomerism c Optical isomerism d Hydrate isomerism

a 32 4 g c 36 0 g equivalent 4 104 b 38 8 g d 22 4 g 48 If 54 g of silver is deposited during an electrolysis reaction how much aluminium will be deposited by the same amount of electric current a 2 7 g b 4 5 g c 27 g 9 The quantity of electricity needed d 5 4 g to to separately