Physical Chemistry Questions

39 When 1 g of anhydrous oxalic acid is burnt at 25 C the amount of heat liberated is 2 835 kJ AH combustion is oxalic acid C H O 2 445 65 kJ 4 155 16 kJ 1 255 15 kJ 3 295 24 kJ

26 Azo isopropane decomposes according to the equation CH3 2CHN NCH CH3 2 g N g C6H14 g It is found to be a first order reaction If initial pressure is Po and pressure of the mixture at time t is P then rate constant K would be 1 K 2 K 3 K K 2 303 t 2 303 t 2 303 t 2 303 log log log log Po 2Po Pt Po Pt Po 250 290 C Po Po P 2P

Crude calcium carbide is made in an electric furnace by the following reaction CaO 3C CaC CO The product contains 85 of CaC and 15 of unreacted CaO a How much CaO is to be added to the furnace charge for each 1000 kg of CaC

47 100 mL of 0 1 N NaOH solution is required for neutralisation of 0 49 g of a dibasic acid What is the molecular weight of the acid a 49 b 98 c 490 d 196

1 Which complex compound will give four isomers a Fe en 3 Cl3 b Co en Cl Cl c Fe PPh3 3NH ClBr Cl d Co PPh3 3Cl Cl3 2000

Exactly 0 2 mole electrons passed through two electrolytic cells in series containing CuSO4 a ZnSO4 respectively How many grams of each metal will be deposited on the respective cathod in the two cells

Express the Rydberg constant R 109678 cm a J atom b J mol

2 Benzene and naphthalene form an ideal solution at room temperature For this process the true statement s is are a AG is positive b AS is positive system c AS surroundings 0 d AH 0 2013 Adv

28 When mercuric Iodide is added to the aqueous solution of potassium iodide 1 The boiling point does not change 2 Freezing point is raised 3 The freezing point is lowered 4 Freezing point does not change SOE

21 CH CH CHO aq Na CO Produ Identify the product 1 3 Hydroxy butanal 2 3 Hydroxy 2 methyl pentanal 3 3 Hydroxy propanal 4 4 Hydroxy 4 methyl pentan 2 on

Rate of which reactions increases with temperature 1 Of any reaction 2 Of exothermic reaction 3 Of endothermic reaction 4 Of None

1 Which of the following does not characterise X rays a The radiation can ionise gases b It causes ZnS to fluoresce c Deflected by electric and magnetic fields d Have wavelengths shorter than ultraviolet rays 1992 1M

For the reaction AB g A g B g AB is 33 dissociated at a total pressure of p Therefore p related to K by one of the following options P JAIPMT 201 1 p K 3 p 4K P 2 p 3K 4 p 8K P

43 Which of the following mixture act as buffer solution 100 128 1 100 ml of 1 M CH COOH 25 ml 5 M NaOH 20 2 150 m 0 1 M HCOOH 20 ml 1 M KOH Q 481 200 ml 0 5 M NH OH 50 ml 2 M H SO 4 100 ml 1 M NH OH 40 ml 1 M HCL

10 mL of gaseous hydrocarbon on combustion gives 20mL of CO and 30mL of H O g The hydrocarbon is 1 CH 2 CH 3 C H 4 C H

a 80 cc 10 gm of a gas at 1 atm and 273 K occupies 5 litres The temperature at which the volume becomes double for the same mass of gas at the same pressure is 273 K b 273 C c 273 C d 546 C

at 27 C then find the NH HS s NH 9 N 9 NH g H S g 3 N g H g KP 16JC11020 2 mol NH HS s is taken 50 of this is dissociated till at equilibrium in 1 litre container Find moles of N are found finally KP if C

What weight in grams is represented by 1 5 moles of sulphur dioxide 1 60 g 3 96 g 2 74 g 4 91 g

20 Which of the following relates to photons both as wave motion and as a stream of particles 1992 1M a Interference c Diffraction b E mc d E hv

The pH of solution is increased from 3 to 6 Its H ion conc will be 1 Reduced to half 2 Doubled 3 Reduced by 1000 times 4 Increased by 1000 times YEXT

13 A reaction is 50 complete in 2 hours and 75 2013 in 4 hours The order of reaction i complete a 1 b 2 c 3 d 0 Karnataka NEET 201

2 A solution which is 10 3 M each in Mn2 Fe Zn and Hg2 is treated with 10 16 M sulphide ion If Ksp of MnS FeS ZnS and HgS are 10 15 10 23 10 20 and 10 54 respectively which one will precipitate first 2003 1M a FeS on b MgS c HgS d ZnS

5 Select the incorrect statement about cathode rays a They travel from cathode to anode b They travel in a straight line in the absence of an external electrical or magnetic field c Their nature is independent of the materials of cathode d Their nature is dependent on the nature of the gas present

A solid AB has ZnS structure If the radius of cation A is 100 pm what is the radius of ani 3

Which of the following lines correctly show the temperature dependence of equilibrium constant K for an exothermic reaction In KA 0 0 1 B and C A B C D L T K 2 C and D

sp We have taken a saturated solution of AgBr K of AgBr is 12 10 14 When 10 7 mole of AgNO3 are added to 1 litre of this solution then conductivity specific conductance of this solution is find as 11x x 10 7 S m units Find the value of x Given molar conductance of Ag Br and NO are 6x10 Sm mol 8 10 3 Sm mol and 7 10 Sm mol

1 Surface tension does not vary with b concentration a temperature e size of the surface d vapour pressure

When solid NH4HS is vaporized and maintained at 20 C the following equilibrium established NH4HS s NH3 g H S g and the total pressure is 0 4 atm When vaporiz in the presence of NH3 in a closed vessel at 20 C the partial pressure of NH3 was 0 5 atm Calculate under equilibrium the mole fractions of NH3 g and H S g A 0 93 0 07 B 0 6 0 4 C 0 75 0 247 D 0 66 0 34

Which one of the following has a different crystal lattice from those of the rest 1 Ag 3 Cu 2 V 4 Pt

285 The entropy of vaporization of benzene is 85 JK mol When 117 g benzene vaporizes at its normal boiling point the entropy change of surrounding is 1 85 J K Out 3 85 x 1 55 J K 2 85 x 1 5 J K 4 None of these

olarity of gm of pure water Mo 1 40M 2 4M 3 55 5M 4 Can t be determined

2 The vapour pressure of pure liquid A is 0 80 atm When a non volatile B is added to A its vapour pressure drops to 0 60 atm The mole fraction of A in the solution is a 0 125 b 0 25 c 0 5 d 0 75

A sample of lithium was burnt in to give mixture of Li O and Li3N The ash was dissolved in 50 meq of HCI and resulting solution back titrated with NaOH 20 meg of NaOH were required to reach the end point An excess of NaOH was then added and solution distilled The ammonia released was then trapped in 10 meq of second acid solution required 6 meq of the base Calculate percentage Lithium burnt to the oxide

Which of the gas will not follow Henry s law HCI 2 He 3 0 2

2 For a given reaction AH 35 5 kJ mol and AS 83 6 J K mol The reaction is spontaneous at Assume that AH and AS do not vary with temperature T 425 K c T 298 K b all temperatures d T 425 K NEFT 2017

5 g of hydrogen reacts with 32 g of oxygen to form moles of water 1 1 3 3 2 2 4 4

Which of following will have maximum pH 1 Human saliva 3 Human blood 2 Black coffee aley 4 Gastric juice

25 0 ml of an iron III solution of unknown concentration were titrated against the standard 0 5M VOSO 2H O solution The average titre value of VO2 ion needed to completely react with the solution containing the Festions was 22 14 ml The mass of VOSO 2H O Mol wt 199 required to make 250 ml of the standard solution is C 12 45 gm D 100 gm A 24 9 gm B 49 8 gm

2 5 mL of M weak monoacidic base K 1 10 at 12 5 25 C is titrated with 217 15 M HCl in water at 25 C The concentration of H at equivalence point is Kw 1x 10 14 at 25 C a 3 7 x 10 13 M c 3 2 x 10 2 M b 3 2 x 10 7 M d 2 7 x 10 2 M 2008 3M

pH of a dilute solution of HCl is 6 95 Calculate molarity of HCl solution 6 95 11 22 10 8 10 7 058 90 10 8 10 C lution K NH

v For each value of n k may have n different values These are 1 2 3 n Thus for the Bohr orbit with n 4 there are four Sommerfeld orbits three elliptical orbit one circular orbit with k 1 2 3 and 4 When k 4 the elliptical orbit reduces to a circular orbit Sommerfeld thus introduced the concept of subshells in a principal quantum shell The difference in energy between any two subshells is quite small The fine structure of hydrogen spectrum can be explained by assuming several transitions between several subshells each characterised by different values of k but same value of n n 4 k 4 n 4 k 3 n 4 k 2 n 4 k 1

56 A volume V of air saturated with water vapour exert a pressure P Pressure of saturated vapour is Po If the volume is made V 2 isothermally the final pressure will be a P c 2P Po VI b 2Po d 2 P Po

Cisplatin an anticancer drug has the molecular formula Pt NH3 2Cl What is the mass in gram of one molecule Atomic weights Pt 195 H 1 0 N 14 Cl 35 5 a 4 98 x 10 21 b 4 98 x 10 22 c 6 55 x 10 21 d 3 85 x 10 22

For a unimolecular if reaction AB has rate constant K another unimolecular reaction CD rate constant K If half life of first reaction is half of half life of second reaction then find Ea Ea will be 1 RT n2 2 RT n2 no 3 RT ln2 wolle 4 1 RTln2

N 3 15 g of ice 4 Same in all 37 Concentrated aqueous sulphuric acid is 98 H SO4 w v and has a density of 1 80 gmL 1 Molarity of solution 1 1 M 2 1 8 M 3 10 M 4 1 5 M 38 An element X has the following isotopic composition 56X 90 57X 8 59X 2 0 The hic mass of the naturally 45 The numb 1 8 3 7 46 Mole frac NaOH 1 0 16 3 0 25 Imp fo Ass

A 100 ml flask containing O at 1 2 atm and 300 K is connected to a 250 ml flask containing NO g at 0 6 atm and 300 K by means of a narrow tube of negligible volume when they combine quantitatively to form NO Finally NO g dimerized partially into N O4 g and pressure inside the flask was found to be 0 41 atm at the same temperature Find dimerization of NO as 2NO g N O g

liquid at room temperature leads to a 0 b At the room temperature the forces are 100 ling effects attraction between the particles of solid substances than those which exist in the gaseous state c The arrangement of particles is less ordered in the order in the state state However there is no

9 The e m f of a Daniell cell at 298 K is E Zn ZnSO CuSO Cu 4 0 01 M 1 0 M when the concentration of ZnSO4 is 1 0 M and that of Cusc is 0 01 M the e m f changed to E2 What is the relationsh between E and E2 1 a E E c E E b E E2 d E 0 E

2 What is correct relation between mole fraction in vapour phase YA of A in terms of X If mole fraction in solution of A is X If PA is vapour pressure of A in pure state 1 1 XA PA 3 1 XAPO Y XA PA 2 1 XA 4 POXA

51 A At equilibrium 1M 1 3 2 2 2 1 B 1M Volume of vessel is 1L 1 mole of D is added from out side Equilibrium was re established keeping temperature constant The amount of C reacts to establish equilibrium is 2 2 1 2 C 2M 4 2 1 2 2 2 2 1 D 1M