Physical Chemistry Questions

125 A saturated solution of Ca3 PO4 2 has Ca 2 1 2 x 10 8 M and PO 1 1 6 x 10 5 M Ksp of Ca 3 PO4 2 is a 3 2 x 10 13 d None of these b 3 2 x 10 34 126 Which of the following is most soluble in water 33 c 2 048 x 101

2A g B g 3C g D g is start with the concentrations of A and B both at an initial value of 1 00 M When equilibrium is reached the concentration of D is measured and found to be 0 25 M The value for the equilibrium constant for this reaction is given by the expression 1 0 75 0 25 0 50 0 75 2 0 75 0 25 0 50 0 25 3 0 75 0 25 0 75 0 25 4 0 75 0 25 1 00 2 1 00 C

9 Arrange the orbitals of H atom in the increasing order of 69 34 their energy 3p 2s 4d 3s 4p 3p 4s 2s 3s 3p 3p 4s 4p 4dxy 2 2s 3s 3p 3p 4s 4p 4dxy 3 2s 3s 3p 3p 4s 4p 4d 4 2s 3s 3p 3p 4s 4p 4dxy xy 4T 3p 2s 4dx 3s 4p 3p 4s xy 1 2s 3s 3p 3p 4s 4p 4d 2 2s 3s 3p 3p 4s 4p 3 2s 3s 3p 3p 4s 4p 4d 4 2s 3s 3p 3p 4s 4p 4d

1 Which of the following hydrocarbon can give only acetone 21 fhio foigh and Butterfa sisiti cuz and CO on ozonolysis in presence of Zinc 1 CH3 CH C CH CH3 2 CH3 CH CH CH C CH3 2 3 CH3 C C CH2 4 CH C C C CH 9 0 9 CH CH S 4 17 3 co 1 CH3 CH C CHCH3e 2 CH3 CH CH CH C CH3 3 CH3 C C CH 4 CH CHIC HC CH CH CH HCM cy

Maxwell said that when electron accelerate they emits electromagnetic radiation Now we can say in reality that electron is not accelerate when it moves circular orbit It accelerate that time when it emits electromagnetic radiation

If pk for fluoride ion at 25 C is 10 84 the ionisation constant of hydrofluoric acid in water at this temperature is 0 3 10 5 05 10 01 10 06 10 Marks 4

water shows depressions in freezing point in the ratio of 4 1 Assuming KCl to be completely ionised the compound X in solution must 1 dissociate to the extent of 50 2 hydrolyse to the extent of 80 3 dimerize to the extent of 50 4 trimerize to the extent of 75

A non volatile solute is added in benzene liquid so that lowering in vapour pressure of benzene is 78mm of Hg at normal boiling point of pure benzene liquid then A Molality of solution is B Molality of solution is 1000 682 682 1000 m m C Relative lowering in vapour pressure is D Relative lowering in vapour pressure is 78 682 78 760

1 Which of the following mixture will lead to the formatio of negatively charged colloid AgI I 1 50 ml of 0 1 M AgNO3 50 ml of 0 1 M KI 2 50 ml of 0 1 M AgNO3 50 ml of 0 2 M KI 3 50 ml of 0 2 M AgNO3 50 ml of 0 1 M KI 4 50 ml of 0 2 M AgNO3 50 ml of 0 2 M KI

38 Adding powdered Pb and Fe to a solution containing 1 0 M in each of Pb 2 and Fe 2 ions would result into the formation of 1 More of Fe and Pb2 ions 2 More of Fe 2 and Pb ions 3 More of Pb and Fe 2 ions 4 More of Fe and Pb

55 The combustion of 10 gm coke raised the temperature of 1 kg of water from 10 C to 50 C If specific heat of water is 1 cal g C then the calorific value of coke is 1 1000 cal 3 3000 cal 56 The heat of combustion of naphthalene C H s at 2 2000 cal 4 4000 cal

4 ve ve ve 17 Given the standard electrode pontentials K K 2 93 V Ag 0 80 V Hg2 Hg 0 79V Mg2 Mg 2 37 V Cr2 Cr Arrange these metals in their increasing order of reducing 0 74 V 17 EP 4 ve ve ve K K 2 93 V Ag 0 80 V Hg2 Hg 0 79V Mg2 Mg 2 37 V Cr2 Cr 0 74 V dan KT ng power agen 1 Ag Hg Cr Mg K 2 Ag Hg Mg Cr K 1 Ag Hg Cr Mg K 2 Ag Hg Mg Cr K 3 Mg K Ag Hg Cr 3 Mg K Ag Hg Cr 4 Ag Mg Hg Cr K 4 Ag Mg Hg Cr K The spntaneous redox reaction s among the following is 18 fe fall ad it 12 x cr

Incorrect statement about CO is Colourless odourless and water insoluble gas It reduces almost all alkali and alkaline earth metal oxides Contains one sigma and two bonds between C and O Highly poisonous in nature

The measurement of the electron position is associated with an uncertainty in momentum which is equal to 1 10 18 g cm s g cm s The uncertainty in electron velocity is mass of an electron is 9 x 10 28 g CBSE PMT 2008 a 1 106 cms 1 1 10 cms 1 1 b 1 105 cms do 8 1 1 10 cms 1 1 d momentum are equal the

62 4 None of these A gaseous reaction 2A g B g 5C g shows increase in pressure from 80 mm to 100 mm in 5 minutes The rate of disappearance of A is 1 4 mm min 3 1 mm min TE 2 8 mm min 4 2 mm min

A mixture of 0 3 mole of H and 0 3 mole of 12 is allowed to react in a 10 litre evacuated flask at 500 C The reaction is H 2HI the K is found to be 64 The amount of unreacted 12 at equilibrium A B C D 0 15 mole 0 06 mole 0 03 mole 0 2 mole

A real gas at a very high pressure occupies more volume than that of an ideal gas under identical conditions A B C less volume than that of an ideal gas under identical conditions Same volume than that of an ideal gas under identical conditions

5 If degree of dissociation of Al2 SO4 3 is 25 in a solvent then NCERT Pg 58 1 Normal boiling point experimental boiling point 2 Normal osmotic pressure 2 experimental osmotic pressure 3 Normal molecular weight 2 experimental molecular weight 4 Normal freezing point freezing point 1 4 x experimental

115 Choose the correct set of True False for following statements 1 Silver chloride is more soluble in very concentrated sodium chloride solution than in pure water ii The pH of a buffer solution does not change on addition of small amount of an acid or a base iii Addition of NH4Cl does not affect the pH of a solution of NH4OH iv Degree of hydrolysis of ammonium acetate does not depend upon the concentration of ammonium acetate solution v A mixture of acetic acid and sodium acetate can act as buffer solution b FTTTF a TTFTT c TFTFT d FFTTT A 1 1

138 What is the molar solubility of Fe OH K 8 0 x 10 6 at pH 13 0 La sp a 8 0 10 18 b 8 0 x 10 15 c 8 0 x 10 17 139 What is the minimum pH necessary to cause a precipitate of Pb OH 8 0 10 K

Question The half life period of a first order reactionis 5 minutes at A 0 1 M If the conc of A is doubled then half life becomes Half Twice Unaltered Three times

1 40 min 2 20 min 3 30 min 4 25 min 80 Correct match is are A 21 6 carat gold has 90 gold B Iron forms alloy with mercury C Invisible image formed due to deposition of silver D D penicilamine used in treatment of excess of Fe 2 ion E Catalyst used in ostwald process is V 05

For the angles of the unit cells shown below the correct option is A Tetragonal 90 90 Y 110 B Hexagonal a 90 90 Y 120 90 90 Y 90 a C Triclinic D Orthorhombic a 90 90 Y 120

3 What are the necessary conditions for an element to dissolve in a metal and form a solid solution accordingly Are the following alloys are soluble or insoluble Explain this with the reasons a Cu Ni b Cu Zn c Cu Pb

6 In the reaction 6 3 2NH4 6NO3 aq 4H aq 6NO g N g 6H O 2NH4 6NO3 aq 4H aq 6NO g N g 6H O 4 1 Sty the reducing agent is 1 NH 2 NO3 3 H aq 4 NO 3LER 1 NH 4 2 NO3 3 H aq 4 NO

117 150 mL of 0 0008 M ammonium sulphate is mixed with 50 mL of 0 04 M calcium nitrate The ionic product of CaSO 4 will be Ksp 2 4 x 10 5 for CaSO 4 a K sp b Ksp 118 In a saturated solution of AgCl NaCl is added gradually The c K sp d None of these ration of Agt is plotted

6 2 g of a sample containing Na CO3 NaHCO3 and non volatile inert impurity on gentle heating loses 5 of its weight due to reaction 2NaHCO3 Na CO3 H O CO Residue is dissolved in water and formed 100 mL solution and its 10 mL portion requires 7 5 mL of 0 2 M aqueous solution of BaCl for complete precipitation of carbonates Determine weight in gram of Na CO3 in the original sample B 1 59 1 06 053

61 The reaction of formation of phosgene from 6 CO and Cl is CO CI COCI The proposed mechanism is 1 CI 2Cl fast ii CI CO COCI fast iii COCI CI COCI Cl slow Find the correct expression of rate law 1 k 1 r k x 2 r k x k 3 r k x 4 None of these CO C1 1 2 CO CI CO C1 1 2 CI 3 6

4 0 0 Four diatomic species are listed below in different 58 HP T sequences Which of these presents the correct order of their increasing bond order ant 15 19 C H NO 0 2 He 0 NO C 0 NO C H 4 No C 0 He V 1 C2 He NO 0 2 He 0 NO C 3 0 NO C2 He 4 NO C2 O He

11 The measurement of the electron position is associated 11 fefa 44 ats f 1x1018 gcm 11 ARE E with an uncertainity in momentum Which is equal to 1x1018 gcm s the uncertainity in electron velocity is mass of electron 9 10 28 g 1 1 x 10 1 cm s 1 2 1 x 109 cm s 1 3 1 x 106 cm s 1 4 1 x 105 cm s 1XX ABP my 43 1 O 1 1 x 1011 cm s1 2 1 x 109 cm s 1 3 1 x 106 cm s 1 4 1 x 105 cm s 1 H 480 hts 3 9 10 28 g b 47 28 T DP X1018 9x1028 fafs 0 053 f fun of Fw

temperature and catalyst intration of reactants pressure in case of gases the experimental conditions such The rate of a chemical reaction at a given temperature may depend on the concentration of one or more reactants and products The representation of rate of reaction in reactants is known as rate law It is also called as rate equation or rate expression ma of concentration of the The results in Table 4 1 clearly show that rate of a reaction decreases with the passage of time as the concentration of reactants decrease Conversely rates generally increase when reactant concentrations increase So rate of a reaction depends upon the concentration of reactants

8 AH H O g 20 KJ mol 1 240 KJ 2 360 KJ 3 360 KJ 4 20 KJ Which of the following statement is incorrect 1 For exothermic reactions He is less than Products 8 Reactants 2 AH of CO g is same as AH of carbon graphite 8 3 All exothermic reactions have a free energy change AG negative 9 4 For a reaction N g O g 2NO g the heat at constant pressure and heat at constant volume at a given temperature are same

A 1 100g sample of copper ore is dissolved and the Cu of it is treated with excess KI The liberated I requires 12 12mL of 0 10M Na2S2O3 solution for titration What is copper by mass in the ore

4 both magnitude and sign of charge 3 The equilibrium constant for A g B g Structure of AB is like H O If bond energy of B bond is 200 kJ mol and that of B B bond is 100 kJ mol the find ASO of above reaction 1 0 53 J mol K A Bg AB 2 d 2 536 J mol K gr 3 550 J mol K 4 5 36 J mol K Alloy is 3 AB g K 100 at 522 Koferi 100 Pep 4 522 K 3 A g B g den ende fa ata 3 100 kJ mol 3 for Kp 100 AB A B200 kJ mol B B 1 0 53 J mol K 2 536 J mol K 3 550 J mol K 4 5 36 J mol K AB g T 522 K p 100 e gro

84 180 Mark for Review Incorrect statement about silicones is Water repelling in nature High dielectric strength Electrical conductors Biocompatible in nature

3 In the Freundlich adsorption isotherm log log p the value of n is m log k 1 any value from 0 to 1 2 a positive integer 3 a negative integer 4 a positive or a negative fractional number n

In which of the following reaction s H O acts as a reducing agent 1 H O 20H 2 2H 0 0 II HOCI H O H O CI O II H O PbS PbSO4 H O O 1 only O 1 and II only O II and III only 1 and un

K for cyano acetic acid is 3 5 10 Then the degree of hydrolysis of 0 05 M sodium cyano acetate solution will have the following value 1 4 559 x 10 6 3 6 559 x 10 6 2 5 559 x 10 6 4 7 559 x 10 6

A photon of 300 nm is absorbed by a gas and 69 then re emits two photons One re emitted photon has wavelength 496 nm the wavelength of second re emitted photon is U759 nm 2 857 nm 4 657 nm 3 957 nm

A container of volume V L contains an equilibrium mixture that consists of 2 mol each of gaseous PC15 PC13 and Cl at 3 atm and TK Some Cl is added until the volume is double keeping P and T constant Calculate moles of Cl added PC15 PCl3 Cl

122 What is the molarity of a saturated solution of CaCO3 Ksp 2 8 10 a 2 6 10 5 b 2 8 10 c 5 2 x 10 5 123 Kp of Zr3 PO4 4 in terms of solubility S is a 108 s sp d 5 6 x 10

75 Energy levels A B C of a certain atom corresponds to 75 increasing values of energy i e EA E E If and A are the wavelengths of radiations corresponding to the transitions C to B B to A and C to A respectively which of the following statement is correct to B 14 2 42 n 0 n 1 n 2 43 2A1 1 2 3 2 2 0 C B A2 A3 2 23 A 73 2 2 2 23 2 2 4 2 773

03 The rusting of iron takes place as follows d 5 49x10 0 C H O 1 H O 1 E 1 23 V 2e Fe s E 0 44 V The AG for the net process is a 322 kJ mol 1 c 152 kJ mol 1 Given the data at 25 C 2H 2e 2e 10 Fe 2 b 161kJ mol d 76 kJ mol 1

A sample of ferrous sulphate and ferrous oxalate was dissolved in dil H 2SO 4 The complete oxidation of reaction mixture required 40mL of N 10KMnO 4 After the oxidation the reaction mixture was reduced by Zn and HH2S4 On again oxidation by same KKMnO 60mL were required Calculate the ratio of milimoles of Fe2 SO4 3 and Fe2C04 7 02 PM

What is the pH of the buffer formed by mixing 50 mL of 0 2 M NaH PO4 with 50 mL of 0 12 M HC Ka1 H3PO4 7 11x10 3 Kaz H3PO4 6 32x10 8 Ka3 H3PO4 4 5x10 13 a 4 05 O b 2 32 O c 7 02 O d 1 97

73 Which of the following species is more soluble in water 1 M OH 2 M OH 3 MOH K p 1 x 10 Kp 1 10 30 K 1 x 10 2 SP

4 a c 1 a b 66 The correct order of the O O bond length in O H O and 66 O H O 0 0 14 15 16 3 c d HO 27 D 2 O is 1 0 H O O 2 0 H O O X 3 0 0 H O X 4 H O 0 0 Rond 180 1 03 H O 0 2 0 H O 03 3 0 03 H O 4 H O O 0 E 2 b c 4 a c

9 A first order reaction is carried out with an initial concentration of 10 mol per litre and 80 of the reactant changes into the product Now if the same reaction is carried out with an initial concentration of 5 mol per litre for the same period the percentage of the reactant changing to the product is 1 40 3 160 2 80 4 Cannot be calculated

3 1 x 100 cm s 4 1 x 105 cm 5 1 7 1 12 In carius method 0 05 gram organic compound gave 0 03 12 Rafafu 0 05 in fe 0 03 TH AgCl gram AgCl The percentage of chlorine in the compound 3 1 x 106 cm 5 will be 4 1 x 105 cm s 1 14 84 axlo 2 18 2 XIV 20 3 27 7 F 105 35 5 7 03 4 64 2 If the radius of ions such as Mg2 Cst 02 S and Cr 13 f3 for Mg Cst F 435 2 18 2 5x29400 3 27 7 4 64 2 Excel 1485 R 1396 52x88 14 84 108 35 93 03 X108 5 crat far

4 None of these 9 Which of the following set of quantum number is correct 9 fe 1 n 4 1 3 m 3 S 0 1 3 2 n 4 1 0 3 n 4 1 4 4 n 4 1 0 3 3 0 4 m 2 S S J S 1 2 1 2 3 336 ml 4 1 2 1 n 4 2 n 4 3 n 4 4 n 4 1 0 1 4 1 0 m 3 m 0 m 4 m 2 S 0 S 11 01 1 J 2 1