Physical Chemistry Questions

The uncertainty in the momentum is four times the uncertainty in position of a particle The minimum uncertainty in the velocity of the particle is I B 2m T D 4m T

Is the reaction correct and is both KOH and Mno2 colo ess Date Alknes alkynes reacts with Balyer s reagent and decolourise it s pink colour 36 Pink colourless KMn 04 H O KOH Mnozt CH CH H 0 0 CH CH2 0 OH OH H hydroxy

The stability of lyophilic colloids is due to Colour of their particles a layer of dispersion medium on their particles the smaller size of their particles the large size of their particles

d we can not predict 31 Given K values of 5 76 x 10 10 and 4 8 x 10 10 for NH4 and HCN respectively What is the equilibrium constant for the following reaction NH aq CN aq 1 2 32 a 0 83 Which in th NH3 aq HCN aq c 8 0 x 10 11 27 6 x 10 10

3 The Kps solubility product for CuCl silver salt is 1 9 0 4 x 10 7 and the molar solubility is given by Solubility S Kps 1 2 1 9 0 4 x 10 7 1 2 Solubility S 4 4 x 10 4 M What is the uncertainty in solubility for CuCl

Schottky defect Equal number of cations and anions are missing from their respective position leaving behind a pair of holes Density decreased C No is high L R R is high Electrically neutral Ex NaCl CsCl KCl KBr F Frenkel defect This type of defect A is created when an ion leaves its appropriate site in the lattice and occupies an interstitial site Density unchanged C No is low L R R is low Ex ZnS AgBr Electrically neutral AgCl etc Note AgBr shows both Schottl a is a SE W ar Ex K

For a chemical reaction A product the mechanism of the reaction postulated was as follows A 8 k g 3B k2 are Elai a1 If the reaction occured with individual rate constants k k and k3 determine activation energy for the overall reaction if the activation energies associated with these rate constants 1 70 KJ k3 2 10 KJ R D S 3 310 KJ Cg 180 kJ mol E2 90 kJ

A certain current liberates 0 5 g of hydrogen in 2 hr How many grams of copper can be deposited by the same current flowing for the same time in a copper sulphate solution 1 12 7 g 2 15 9 g 3 31 8 g 4 63 5 g

0 The threshold wavelength for ejection of electrons from a metal is 330 nm The work function for the photoelectric emission from the metal is h 6 6 1034 J s A 1 2 x 10 18 J C 1 2 x 10 12 J B 6 0 10 19 J D 6 0 10 12 J

Choose the correct statement 1 dyz orbital lies in the xz plane II p orbital lies along x axis III Lobes of px orbital are at 90 with z axis IV Lobes of dxy orbital are at 90 with z axis Choose only 1 answer A III IV B II III C 1 11

What will be the enthalpy of combustion of carbon to produce carbon monoxide on the basis of data given below C s O2 g CO2 g 393 4 kJ CO g 2O2 g CO2 g 283 0 kJ Question Type Single Correct Type 1 2 676 4 kJ 676 4 kJ

In an experiment m grams of a compound X gas liquid solid taken in a container is loaded balance as shown in figure I below In the presence of a magnetic field the pan with X is ei deflected upwards figure II or deflected downwards figure III depending on the compoun Identify the correct statement s 1 Balanced Magnetic field absent m X 11 Upward deflection Magnetic field present N magnet S A If X is H O I deflection of the pan is upwards B If X is K4 Fe CN 6 s deflection of the pan is upwards C If X is O g deflection of the pan is downwards D If X is C6H6 1 deflection of the pan is downwards III Downward deflection Magnetic field present N S

a 9 5 b 1 c 10 5 d 17 36 Given the two concentration of HCN K 10 are 0 1 M and 0 001 M respectively Wh will be the ratio of degree of dissociation a 1 9 0 1 c 0 003 d 0 01

32 One litre of a solution contains 15 12 g of HNO3 RITAN and one litre of another solution contains 3 2 g of NaOH In what volume ratio must these solutions be mixed to obtain a neutral solution 1 3 Im 010 L 2 4 2 N 3 3744

a 3 11 c 12 d 13 28 What is the pH of a solution in which 10 0 mL of 0 010 M Sr OH is added to 10 0 mL of 0 010 M HCl a 2 30 b 1 50 11 70 d 7 00 29 At 90 C pure water has H 106 M If 100 mL of 0 2 M HCl is added to 200 ml of 01

was observed that in a reaction on doubling the concentration of reactant rate remains unaffected The order of the reactio A

An element crystallizes in FCC with edge length equal to 1600 pm Calculate maximum radius of an atom which can fill the tetrahedral void without distorting the lattice O 45 2pm O 90 2pm O 180 2pm 90 2A

1 The reduction potential of hydrogen half cell will be negative if a p H 1 atm and H 2 0 M b p H 1 atm and H 1 0 M c p H 2 atm and H 1 0 M d p H 2 atm and H 2 0 M potentials for 7 17

AH Alattice H hyd sol For one mole of NaCl s lattice enthalpy 788 kJ mol and H 784 kJ mol from the sol MA hyd 788 kJ mol 784 kJ mol 4 kJ mol The dissolution of NaCl s is accompanied He literature L

11 A bubble of gas released at the bottom of a lake increases to eight times its original volume when it reaches the surface Assuming that atmospheric pressure is equivalent to the pressure exerted by a column of water 10 m height the depth of the lake is a 80 m b 90 m c 40 m e 70 m d 10 m Korala DMTY

We have taken a saturated solution of AgBr Ksp of AgBr is 12 x 10 14 Given 8x10 Smmol 1 20 7x10 Sm mol 1 20 Ap 6x10 5 m mor 20 Br NO3 If 10 7 mole of AgNO3 are added to 1 litre of this solution conductivity specific conductance of this solution is cx10 7 S m1 The val Answer

a Find the location of elements with Z 12 16 8 18 b Find the elements in the above se t that are members of the 1 same grou p and 2 same period c Write the electrnic configuration o f an element X with atomic number 7 P redict the formula of its oxide Is it a m etal or a non metal

Freezing point lowering expression is AT Km molality Which of the following assumptions are considered for the validity of above equation A The solution is dilute B The AH latent heat of fusion of solvent is independent of temperature between the actual and normal freezing point C The solid phase consists of pure solvent when solution is allowed to cool D AT is not equal to 3K for 3 mol L solution

Find molar conductance of NH OH at infinite dilution Given A Ba OH 2 A Ba BaCl 2A NH C 1 251 5 sm mol 1 523 Sm mol 280 Sm mol 130 Sm mol 2 350 sm mol 1

h Kw KxK 14 10 10 x 10 10 14 x 10 10 10 102 BEGINNER S BOX 2 When sodium acetate CH COONa is added to aqueous solution of acetic acid CH COOH the 1 the pH value becomes zero 2 pH value remains unchanged

Choose the incorrect statement A The molar free energies of two phases of the same single substance in equilibrium with another at a given P and T are equal B At the boiling point of liquid entropy of vaporisation is the enthalpy of vaporisation per degree absolute temperature C In an endothermic reaction entropy of the universe increases D AUVs 0 at equilibrium

are fuf vedox rex 3 I which of the 4 F following Rexn 3 After IIII III III 1 I CuO s H g Cu s H O g II Fe O3 s 3CO g 2Fe s 3CO g III 4BCl g 3 LiAH s 2B H g 3LiCl s 3AICI s IV 4NH g 50 g 4NO g 6H O g 1 2 3 4 344

7 Which statement a Conductance with dilution is not correct of an electrolytic solution increases of an electrolytic solution decreases c Specific conductance of an electrolytic solution decreases with dilution b Conductance with dilution d Equivalent conductance of an electrolytic solution increases with dilution highest

c just greater than 6 d just less than 7 24 10 5 M NaOH solution at 25 C is diluted 1000 times The pH of the resultant solution w blie between 7 and 8 d remain unchanged a be equal to 8 c lie between 6 and 7

For the reaction equilibrium mixture contained 3 moles each of PC15 PCl3 and Cl If the total pressure is 3 atm What is the value of Kp decomposition of gaseous PC15 A 1 B 3 C 4 D 6 for the

49 The atomic number of an element is 17 The number orbitals containing electron pairs in the valency shell is a 8 93 of the d 6 alomo

Consider the FeO solid Due to strong heating some Fe ions get oxidised to Fe and the stoichiometry gets disturbe It is found that out of 8 iron ions there are 7 Fe and 1 Fe ton present The formula of the given FeO solid should be O FeO OF 0 Fe 0

126 Which of the following is most soluble in water a Ba3 PO4 2 Kp 6 10 3 c Fe OH 3 Kp 6 x 10 38 b ZnS Kp 7x10 16 sp d Ag 3 PO4 Ksp 1 8 x 10 18 127 Silver ions are added to a solution with Br 1 1 1 CO 1 JAS 0 1 01

Consider a 3 D close packing of ABAB type The radius of an atom is 100 dentify the correct statement s The distance between A B layor 163 3 pm The distance between B B layer 266 6 pm The distance between B A layer 133 3 pm The shortest distance between the Iwo aloms 163 3 pm 2233

is not 5 For which electrolyte the evaluation of A possible by extrapolation of A vs c curves to zero concentration a KCI c NaCl b NH4OH d K SO4 otus in which electrical energy is converted

c Isol 179 Photoelectric emission is observed from a surface for frequency v and v2 of the incident radiation V V If the maximum kinetic energies of the photoelectrons in the two cases are in the ratio 1 k then the threshold frequency Vo is given by V2 V1 k 1 3 a c kv 2 V1 k 1 kv1 V2 k 1 14 d 2 V2 V1 k orhitals of element with ato

a none of 142 How many electrons with 1 3 are there in an atom having atomic number 54 a 3 b 10 c 14 d None of these 143 The electronic configuration of an element is 1s 2s

Equal volumes of three acid solutions of pH 3 4 and 5 are mixed in a vessel What will be the H ion concentration in the mixture 1 1 11 x 10 3 M 3 3 7 x 10 4 M AIPMT Prelims 2008 2 1 11 x 10 4 M 4 3 7 x 10 3 M

22 Calcium hydroxide is a strong base Compute Ca 2 and OH for a solution that is prepare by dissolving 0 60 g of Ca OH in enough water to make a 1500 ml of solution Atomic mass Ca 40 0 16 H 1 a 5 4 x 10 3 9 1 x 10 13 3 c 5 4 x 10 5 4 x 10 3 3 b 5 4 x 10 3 1 08 10 2 d 8 1x10 3 8 1x 10 3

a 3 70 10 70 b 3 30 10 30 c 3 70 27 What is the pH of a solution in which 25 0 mL of 0 1 M NaOH is added to 25 mL of 0 08 M HCl and final solution is diluted to 500 mL a 3 11 C c 12 of d 13 10 M STOH is added to 19 0 mL of

246 The quantum number for the last electrons of an atom are n 2 1 0 m 0 s 1 2 The atom is Ca lithium b boron d hydrogen c carbon 17 7 The mannetic moment of electron in an atom excluding

200 gms of marble chips are dropped into one kilogram of solution of HCI conta tenth of its weight of the pure acid How much of chips will remain undissolved What anhydrous calcium chloride and what weight of CO2 gas could be obtained from it

26 A 25 0 mL sample of 0 10 M HCl is titrated with 0 10 M NaOH What is the pH of the solution at the points where 24 9 and 25 1 mL of NaOH have been added a 3 70 10 70 b 3 30 10 30 c 3 70 10 30 d 3 0 11 0 What is the all of anlution in which 250 ml of 0 1 M NaOH is added to 25 mL of 0 08 MHC 377 37

2 50 ml of a water sample requires 9 2 ml of N 50 HCI up to phenolphthalein end point and total 13 1 ml of the acid for complete neutralization Find the types and amount of alkalinity in the water sample

Lattice enthalpy of nacl is 788 kj mol and hydration enthalpy of nacl is 784 kj mol Now solution of enthalpy is 4 kj mol Then how I can identify bond of nacl may be dissociated or non dissociated 10 01 RM

d Ca 12 An electron that has the quantum number n 3 and dm 2 a must have spin value 1 2 b must have 1 1 c must have l 0 1 or 2 must have 1 2 5 The funda l nton 21 1912

An organic compound A CxH O was treated with 12 NaOH consumes 6 moles of 1 to produce iodoform and a dibasic acid B which when treated with alkaline KMnO4 pink color of KMnO4 gets decolorized with no organic compound left as residue The minimum value of X is

33 Mrs Usha a science teacher performed the following experiments Experiment 1 She heated sugar in a China dish A black substance was obtained along with caramel fumes Experiment 2 She mixed sand and crushed naphthalene balls in a China dish Then she covered the China dish with a watch glass with some ice kept on it and heated Crystals of pure naphthalene were seen on the underside of the watch glass A B Identify the changes taking place in these experiments Experiment 1 Chemical change Crystallisation Experiment 2 Physical change Decomposition Experiment 1 Physical change Crystallisation Experiment 2 Chemical change Sublimation Experiment 1 Physical change Crystallisation Experiment 2 Physical change Crystallisation Experiment 1 Chemical change Decomposition C D Experiment 2 Physical change Sublimation and

9 Which of the following expressions correctly represents the equivalent conductance at infinite dilution of Al SO4 3 Given that 1 and SO are the equivalent conductances at infinite dilution of the respective ions So a 2 3850 b SO c A1 0 6 SO4 1 2 SO 1 d 2 A1 Mains 2010

Q 36 At 300 K the rate of decomposition of a gaseous compound initially at a pressure of 20 kPa was 13 5 Pas when 10 had reacted and 0 5 Pas when 70 had reacted Then Calculate order of reaction is Chestik emistarpel