Physical Chemistry Questions

Predict which of the following reaction s has a positiv entropy change 1 Ag aq Cl aq AgCl s ii NH4Cl g NH3 g HCl g iii 2NH3 g N g 3H g 1 i ii 2 iii 3 ii iii

1 100 C 2 0 C 3 373 K 4 273 C 24 The molar entropy of the vapourization of acetic acid is 14 4 cal K mol at its boiling point 118 C The latent heat of vapourization of acetic acid is 1 49 cal g neet prep This solute may be 1 CaSO4 2 CuSO4 temperature and is given as S Ae AH RT Here AH is enthalpy of the solution For the gir solute variation of log S with temperature can be sho by the figure given below log S 1 T Mini Test 17 Spontaneity Entropy Contact Number 9667591930 85275211

65 A weak acid HA with an ionization constant of approximately 10 is prepared in a 1 0 molar aqueous solution What will happen to the percent dissociation of this acid as more pure water is added to the solution 1 Percent dissociation remains unchanged 2 Percent dissociation will increase 3 Percent dissociation will decrease 4 The ionization constant will increase If the solubility of A X BX and CX salts are 65 X 66 3 10 7 10 31 facen 1 2 f 3 waard 4 3 afe aut

The value for the standard emf electromotive force of a galvanic cell described by the balanced chemical equation is 0 79 V Determine the value of the standard half cell potential for the I 12 couple Cr202 7 aq 21 aq 12 g Cr3 aq E Cr 20 7 2 Cr 3 1 33 V A 0 18 V B 0 18 V C 0 54 V D 0 54 v

Balance the following reactions a Mg N Mg3N2 b PCL5 H O H3PO4 HCe c d e f h i Al Fe3O4 Al O3 Fe MnO HCl MnCl Cl2 H O Na S O3 12 Nal NaS O Sn NaOH Na SnO H P4O10 H2O H3PO4 Al2 SO4 3 NaOH Al OH 3 Na SO4 CH3OH O2 CO H O Ammonium chloride and barium hydroxide is heated and the compounds react to ammonium gas barium choride and water Remember to include phase labels

Which of them is correct statement O Cu can be recovered by CuSO4 by use of Zn O Zn can be recovered by ZnSO4 by use of Ag O Cu can be recovered by CuSO by use of Ac O Zn can be recovered by ZnSO4 by use of Cu

Which of the following pairs of a chemical reaction certain to result in a spontaneous reaction 1 Endothermic and decreasing disorder 2 Exothermic and increasing disorder 3 Endothermic and increasing disorder 4 Exothermic and decreasing disorder

The standard electrode potentials for the reactions Ag s Ag aq e Sn aq 2e Sn s at 25 C are 0 80 volt and 0 14 volt respectively The standard emf of the cell Sn Sn 1M Ag 1M Ag is 1 0 66 volt 2 0 80 volt 3 1 08 volt 4 0 94 volt

which of the following curve is are correct A B Free energy A g B g K 1 G Pure A Free energy Pure A Free C energy D 1 0 Pure A X 0 5 X 0 5 A g B g K 1 X 0 5 x 0 5 A g B g K 1 Pure B G T T T T A Ideal gas 200 400 600 p 101 325 kPa X 0 5 Pure B X 0 5 OR Pure B

Collect the following solids grannular sugar common salt blue vitriol Observe a few grannules of these solids under a magnifying lens or microscope Discuss your observations with reference to the following points i Shape of the grannules ii Smoothness of faces of the grannules and iii Angles between various edges of the grannules All the above solids are crystalline solids Name the properties of crystals that you observed in this activity SALT

war the equilibrium AB g A g B g K is equal to four times the total pressure The number of moles of A formed is x3 S Mi 1 12 2 3 5 9 P xx 7 el 4KP 2 2 p 4pp kef 2 AJB A JAB 4 5

A 1 96 solution of H SO4 in water freezes at 0 794 C If K of water is 1 86 K kg mol and density of solution is 1 0 g mL the value of ionization constant for the following reaction is HSO4H SO a 0 146 c 2 104 b 4 10 d 5 10 6

50 ml Toluene CH CH g undergoes combustion with excess of oxygen Calculate the volume contraction A 50 ml B 150 ml C 75 ml D 100 ml The questions below to consist of an Assertion and the Reason Mark appropriate option using the given directions

6 The following equilibrium constants are given N 3H 2NH3 K N O22NO K H 0 H O K The equilibrium constant for the oxidation of NH3 by oxygen to give NO is a K K3 K K K b K3 K3 K K K

a 20 kJ c 115 kJ d 0 115 kJ The solution of CuSO4 in which copper rod is immersed is diluted to 10 times the reduction electrode potential a increases by 0 030 V c increases by 0 059 V b decreases by 0 030 V d decreases by 0 059 V

1 2 3 4 ARJUNA JEE Mole Concept Continued Based on the following consecutive reactions 2KCIO 2KCI 30 4A1 30 2Al O3 2 moles of KCIO of 50 purity on strong heating and then with excess of Al Al2O3 formed is A 2 mol C 3 mol In the following set of reactions CaCO CaO CO 75 yield CO C2CO 50 yield CO formed at STP from 10 g of CaCO is A 2 24 L B 11 2 L C 1 12 L D 1 68 L II III B 1 mol D 1 5 mol NH is formed in the following step Ca 2C CaC 50 yield L CaC N CaCN C 100 yield CaCN 3H 0 2NH3 CaCO 50 yield 2 moles of NH are formed if we take A 1 mol Ca B 2 mol Ca C 3 mol Ca D 4 mol Ca What weights of P O and P O will be produced by the combustion of 31 g of P in 32 g of oxygen leaving no Pa and O A 2 75 g 219 5 g B 27 5 g 35 5 g C 55 g 71 g D 17 5 g 190 5 g 5 How many moles of P4O6 and P4O10 will be produced by the combustion of 12 4 gm of phosphorus in 12 8 gm of Oz leaving no Pa or 0 Atomic wt P 31 A 0 11 mol and 0 3 mol B 0 15 mol and 0 25 mol C 0 05 mol each D 0 1 mol each 6 If we start from 500 g of CaCO3 and treated with series of reagents to give C H o find mass of CsH formed if molar mass of CaCO is 100g and CsHio is 58 g B 116 g A 58 g C 168 g D 224 g 7 For sequential reaction A B C 2B C 2D If yield of i and ii reactions are 90 and 80 respectively then the overall yield is expected to be A 90 C 72 A 42 gm C 14 3 gm i ii B 80 D 10 8 NX is produced by the following step of reactions M X MX 3MX2 X M Xs MiXs N CO3 NX CO M 0 How much M metal is consumed to produces 206 gm of NX Take at Wt of M 56 N 23 X 80 B C Z F A 3 moles C 5 moles DPP 07 B 56 gm D 7 4 gm 5 moles of A 6 moles of Z are mixed with sufficient amount of C to finally produce F Then find the maximum moles of F which can be produced Assuming that the product formed can also be reused Reactions are A 22 1 B 4 5 moles D 6 moles 10 Human lungs can absorb 8 gm O per hour by respiration If all oxygen atoms are converted to carbohydrates C6H12O6 how long will it take to produce 180 gm C6H12O6 A 8 hours B 12 hours C 10 hours D 6 hours

The cell reaction for the given cell is Pt H pH 2 pH 3 Pt H P 1 atm P2 1 atm a spontaneous c in equilibrium b non spontaneous d either of these ricity is passed through CuSC

6 On adding AgNO3 solution to KI solution a negatively charged colloidal solution will be formed in which of the following conditions a 100 mL of 0 1M AgNO3 100 mL of 0 1M KI b 100 mL of 0 1M AgNO3 50 mL of 0 2M KI c 100 mL of 0 2M AgNO3 100 mL of 13 0 0 1M KI d 100 mL of 0 1M AgNO3 100 mL of 0 15M KI

An ideal solution was found to have a vapour pressure of 80 torr when the mole fraction of a non volatile solute was 0 2 What would be the vapour pressure of the pure solvent at the same temperature Question Type Single Correct Type 1 2 3 64 torr 80 torr 100 torr 100 torr

5 Ag O H O 2e2Ag 2OH In the above chemical reaction 1 Water is oxidised 2 Silver is oxidised 3 Silver is reduced 4 Hydrogen is reduced imited Regd Of

Electrons in a sample of H atoms make transition from state n x to some lower excited state The emission spectrum from the sample is found to contain only the lines belonging to a particular series If one of the maximum energy photons has an energy of 0 6375 eV find the value of x 3 Take 0 6375 eV 0 85 eV 4

2 When H SO3 is converted into H SO4 the change in the oxidation state of sulphur is from 1 0 to 2 2 2 to 4 3 4 to 2 4 4 10 6 3 respect 1 4 3 2 4 3 3 2 3 4 2 3 8 Which 1 HNC

For the redox reaction Zn s Cu 0 1M Zn 1M Cu s taking place in a cell E Cell is 1 10 volt Ecell for the cell will be RT F 2 303 1 1 07 volt 3 2 14 volt 0 0591 2 0 82 volt 4 1 80 volt

29 Which of the following statements is are true 1 Point An oil can be pumped easily below cloud point An oil can be pumped easily above cloud point An oil can be pumped easily below pour point

Container Gas Formula Molar mass g mol Temperature C Pressure atm B Ethane CHA C H6 A Methane 16 27 2 0 30 e density of the gas in g L is Ogreatest in container A O greatest in container B Ogreatest in container C the same in all three containers 27 e average kinetic energy of the gas molecules is Ogreatest in container A O greatest in container B O greatest in container C the same in all three containers 4 0 the pressure of each gas is increased at constant nperature until condensation occurs which gas Il condense at the lowest pressure Methane Ethane O Butane O All the gases will condense at the same pressure Butane C4H10 58 27 2 0

A certain organic compound A decomposes by two parallel first order mechanisms A k k If ky k 1 9 and k 1 310 is 1 Calculate the concentration ratio of C to A if an experiment is started with only A and allowed to run for one hour A Answer Your Attempt 0 525 0 62 0 81 Correct answer Rate this ques

ZnS is not precipitated by passing H S in acidic medium 3 4 14 but CuS is precipitated The reason for it is 4 4 14 1 Ksp CuS Ksp ZnS 2 Ksp CuS Ksp ZnS 3 Ksp CuS Ksp ZnS 4 none of these 27 When ec which c Kp of

AB is a strong electrolyte and AC a weak electrolyte Both are dissolved in water separately and their solutions are mixed together Question Type Single Correct Type 1 The degree of ionisation of AC will decrease 2 The degree of ionisation of AB will decrease 3 AB will be precipitated 4 AC will be precipitated

9 For which of the following parameters the structural isomers C ll5OH and CH3OCH 3 would be expected to have the same values assume ideal behaviour 2004 1 Heat of vaporization 2 Gaseous densities at the same temperature and pressure 3 Boiling points

When H S is passed through an aqueous solution of an equimolar mixture of Zn and Pb acidified with dilute acetic acid ZnS is not precipitated because 1 Ksp ZnS Ksp PbS 2 Kap ZnS Ksp PbS 3 H S decreases the Ksp of Zns 4 H S increases the Kp of PbS Fill OMR Sheet If above link doesn t work please go to test link from where you got the pdf and fill OMR from there

The reaction of carbon monoxide and iodine pentoxide as represented by the equation 2 is endothermic in nature Explain the effect by which we can increase the product formation 5 CO g I Os g 1 g 5 CO g

An acid is a component of rancid butter and has a vile stench Burning 0 44 g of the acid in excess oxygen yield 0 88 g o f CO2 and 0 36 g of H20 as the only pro ducts Given that the acid contains only C H and O and if vapour density of the acid is 44 then which of the following o ptions is not correct about it s molecula r formula Please explain in an easy ma nner I dont understand why one mole will be equal to 0 04mol of hydrogen

Paragraph for Q Nos 4 to 5 12 mL gaseous mixture of an alkane and an alkene contain ing same number of carbon atoms require exactly 285 mL of air containing 20 v v O and rest N for complete com bustion at 200 K After combustion when gaseous mixture is passed through KOH solution it shows volume contraction of 36 mL 4 Formula of alkane is a C5H 2 b CH c C H6 d C4H10 5 Mole fraction of CO in final gaseous sample is 6 d 4 13 a 6 b 6 13 c 6 14

5 neet prep Mini Test 20 Solubility Product mol L Then find out Ksp of electrolytes 1 5 x 10 2 25 10 10 3 1 x 10 13 13 P Contact Number 9667591930 852752171 25 There sparingly soluble saltrs A X AX and AX3 have the same solubility product Their solubilities will be in the order 1 AX AX A X 2 AX A X AX

25 There sparingly soluble saltrs A X AX and AX3 have the same solubility product Their solubilities will be in the order 1 AX AX A X 2 AX3 A X AX 3 AX AX3 A X

4 21 Calculate the rate constant The following data were obtained during the first order thermal decomposition of SO Cl at a constant volume so Cl g SO g Cl g 2 Experiment Time s Total pressure atm 1 0 2 100 alculate the rate of the reaction when total pressure is 0 65 atm 0 5 0 6

c 38 For the cell reaction Fe 2Fe 3Fe2 which is not possible a One cell can be constructed b Three different cells with different Ecell are possible c Three different cells with different number of electrons used in redox reaction are possible d Three different cells with same AG value a possible

monobasic acid is 4 S cm mol 1 and a infinite dilution is 200 S cm mol 1 Dissociation constant of this acid is 10 3 4 x 10 6 2x 10 5 10 4

3 If E Au Au 0 volt then E is 1 69 volt and E Au Au 3 1 0 19 V 3 1 255 V will be 3 Au Au 2 1 255 V 4 2 51 V is 1 40 83

27 Find qvibrational for each of the molecules at 675K a 0 2 b CH C CO d H o e CO UPDATE The only other information is that these values may be needed to calculated as well in order to find the answer qtrans V and qrotational This is all of the information given THIS IS A VALUE RELATED TO THE PARTITION FUNCTION THE ANSWER IS NOT THE VIBRATION MODE

4 For the following reaction pick out the incorrect interpretations 2A g B g 4C g D g 1 2 moles of A 1 mole of B reacts to form 4 moles of C 1 mole of D 2 2 gm of A 1 gm of B reacts to give 4 gm of C 1 gm of D 3 2 molecules of A 1 molecule of B reacts to give 4 molecules of C 1 molecule of 4 2 vol of A 1 vol of B reacts to give 4 vol of C 1 vol of D At STP

For each of the following determine if the first item or the second item has the larger entropy NO g OR NO2 g A Second item B First item SO3 g OR S S Ice at 40 C OR Ice at 4 C CO g or CO2 g

At 25 C the standard emf of cell having reactions involving two electrons change is found to be 0 295 V The equilibrium constant of the reaction is 1 29 5 x 10 2 3 1010 2 10 4 29 5 1010

2 If 100 g of Na SO4 is dissolved in 200 g of H O and the solution is cooled until 100 g of Na SO4 10H O crystallizes out find a The composition of the remaining solution mother liquor b The grams of crystals recovered per 100 g of initial solution

Select the incorrect statement regarding the boiling points of alkanes a boiling point increases with stronger van der Waal s forces MHT CET Chemistry b surface area is the only factor which determines the boiling point of alkane 11 00 25 12 37 An ma c a boiling point of straight chain alkanes is greater than that of branched chain alkanes c d the boiling point of cycloalkanes is always 38 Alk

Consider the following solution 1 M aqueous glucose 1 M aqueous NaCl 1 M aqueous calcium phosphate 1 M benzoic acid in benzene Select the correct statements for the above solutions I II V O all are isotonic solution O III is hypertonic than I II IV IV is hypotonic than I II III Il is hypotonic than III but hypertonic than I and IV

18 Antistokes lines in Raman spectra is observed when d Av V V is ve c Vi V s a V V b Vi VS 19 Intensity of stokes lines is

The molality of 1 litre solution with y w v of CaCO is 2 The weight of the solvent present in the solution is 450 g then value of y is At wt Ca 40 C 12 0 16

A chemist isolated a protein from crab and wanted to determine its molecular weight Which of the following method would give the best result for him A Elevation in boiling point B Relative lowering of vapour pressure C Depression in freezing point D Osmotic pressure method

AgNO3 aq was added to an aqueous KCl solution gradually and the conductivity of the solution w measured The plot of conductance A versus the volume of AgNO3 is A P C R A volume P yu H volume S volume Q volume R B Q D S