Physical Chemistry Questions

1 2 2 3 0 4 14 The activation energy for the reaction C 02 H O H O 0 H O 1 20 is 18 K cal mol at 300 K calculate the fraction of molecules of reactonts having energy equal to or greater than activation energy Anti log 13 02 9 36 10 4 1 9 36 x 10 14 2 1 2 10 12 4 5 2 x 10 15 3 4 2 10 16 Which of the following is falso about catalud

The standard heats of formation of CH CO C and H O0 are 76 2 394 8 and 241 6 KJ moll respectively Heat evolved by burning 1m methane measured under normal condition will be 1 801 8 KJ KJ 3 890 KJ KJ ideal gas expand isothermally a 2 35794 6 4 3570

WORK DONE IN DIFFERENT PROCESS 40 The work in ergs for a reversible expansion of one mole of an ideal gas from a volume of litres to 20 litres at 25 C is 10 1 2 303 x8 314 x 10 x298 log2 2 2 303 x0 0821 x 298 log2 3 2 303 x0 0821x298 log 0 5 4 2 303 x2x298 log2 TH0043

1 Spontaneous 3 At equilibrium 54 If A H 0 and AS spontaneously when 1 AH 0 3 AH TAS 2 Non spontaneous 4 Can t say anything TD0069 0 the reaction proceed 2 AH TAS 4 None

57 For the reaction A s B s C g the value of AH 30 56 kJ mol and AS 66 JK mol The temperature at which the free energy change for the reaction will be zero is 1 373 K 3 463 K 2 413 K 4 493 K

5 42 The decomposition te e t CK0044 of N O occurs as O and follows first order 2N O 4NO kinetics hence 1 The reaction is bimolecular 2 The recation is unimolcular 3 t 2 a a 4 a

CK0061 7 Doubling the initial concentration of a reactant doubles of the reaction then order of the reaction is 2 2 1 3 3 1 4 0

9 According to the following reaction C s 1 2O g CO g AH 26 4 kCal 1 CO is an endothermic compound 2 CO is an exothermic compound 3 The reaction is endothermic 4 None of the above

CK0064 50 A substance A decomposes in solution following the first order kinetics flask I contains 1 L of 1M solution of A and flask II contains 100 ml of 0 6 M solution After 8 hr the concentration of A in flask I become 0 25 M what will be the time for concetration of A in flask II to become 0 3 M 1 0 4 hr 2 2 4 hr 3 4 0 hr 4 Unpredictable as rate constant is not given CKOOCE

4 None TD0083 75 If the equilibrium constant for a reaction is 10 then the value of AG will be R 8JK mol T 300 K 1 5 527 kJ mol 3 55 27 kJ mol 2 5 527 kJ mol 4 55 27 kJ mol

1 A BC D AH 10 000 J mol AS 33 3 J mol K At what temperature the reaction will occur spontaneous from left to right 1 300 3 K 2 300 3 K 3 300 3 K 4 None of these

Pre Medical Chemistry 61 39 For the reaction 2NO C 2NOCI the following mechanism has been proposed NO CI NOCI fast NOCI NO 2NOCI slow the rate law for the reaction is 1 Rate KINOPICLI KINO CI 2 2 Rate Rate

TROPY SECOND LAW OF THERMODYNAMICS For which reaction from the following AS will be maximum 1 Ca s 1 2O g CaO s 2 CaCO s CaOs CO g 3 C s O g CO g 4 N g O g 2NO g TD0047 MENGMODULE 1STHERMODYNAMICS102 EXE P65

For the reaction 2A B CA B C the rate law has been determined to be Rate K A B C If the value of the K is 2 0 x 10 6 mol 2 L S 1 for the reaction Initial rate of the reaction with A 0 2 mol L 1 B 0 1 mol L 1 C 0 5 mol L is 1 2 x 10 9 Ms M 1 2 4 10 9 Ms 9 M 1

When a rod of metallic lead was added to a 0 01 M solution of Colen 3 it was found that 68 of the cobalt complex was reduced to Colen 32 by the lead Epb 2 Pb s 0 126 V AG of the reaction is A 10 34 kJ B 10 34 KJ

CK0057 1 For a given reaction of first order it takes 20 minute for the concentration to drop from 1 M to 0 6 M The time required for the concentration to drop from 0 6 M to 0 36 M will be 1 More than 20 min 2 Less than 20 min 3 Equal to 20 min

For a given reaction AH 30 kJ mol 1 and AS 40 JK 1 mol 1 The reaction is spontaneous at 300 K 550 K 800 K 650 K

7 A first order reaction is 50 completed in 2 minutes at 27 C and 5 minutes at 47 C The ener of activation of the reaction is 1 43 85 KJ 3 11 97 KJ 2 55 14 KJ 4 6 65 KJ

46 Which among the following state symbols are possible for the element X with atomic number 5 A P P and P B P 3 2 and P1 2 C S1 2 and So D P 1 2 P 3 2 and P5 2

8 In a first order reaction the a la x was fou to be 8 after 10 minute The rate constant i 1 2 303x3log2 10 2 2 303 x 2log 3 10 3 10 x 2 303 x 2log3 4 10 x 2 303 x 3log2 6400

5 The heat of combustion of ethanol determined in a bomb calorimeter is 670 48 kCal mole at 27 C What is AH at 27 C for the reaction 1 335 24 kCal 3 670 48 kCal 2 671 08 kCal 4 670 48 kCal E max 1 C 2 C 3 C

49 75 of a first order reaction was found to complete in 32 min When will 50 of the same reaction complete 1 24 min 3 8 min 2 16 min 4 4 min 56

A chemical reaction 2A4B C in gaseous phase shows an increase in concentration of B by 5x10 M in 10 second The rate of reaction and rate of appearance of B are respectively 1 5 x 10 4 MS and 1 25 x 10 Ms 5 x 10 4 Ms 1 2 1 25 x 104 Ms and and 3 1 25 x 10 4 Ms 1 4 2 5 x 10 4 MS 1 2 5 x 10 4 Ms and 1 25 x 104 Ms

In a reaction 2A products the concentration of A decreases from 0 5 mol L to 0 4 mol L in 10 minutes rate of reaction is 1 0 005 mol L min 2 0 002 mol L min 3 0 05 mol L min 4 0 02 mol L 1 min1

3 890 KJ 4 3570 10 moles of an ideal gas expand isothermally and reversibly from a pressure of 5 atm to latm at 300 K what is work done 1 40 15 x 10 J 2 20 30 10 J 3 18 x 10 J 4 55 x10 J Enthaly of formation of H O is 68 Kcal mole 13 126 6 201 20 and 1 218 4 JK ma 2 318 4 J K ma 3 520 2 J K ma 4 128 6 JK me Out of E H q War 1 E H W

3 For the reaction CO g O g CO g Which one of these statement is correct at constant T and P 1 AH AE 2 AH AE 3 AH AE 4 AH is Independent of physical state of reactants

0 A 1 250 g sample of octane CH is burned in excess of oxygen in a bomb calorimeter The temperture of the calorimeter rises from 294 05 K to 300 78 K If heat capacity of the calorimeter is 8 93 KJ K enthalpy of combustion of the sample of octane is 1 6285 KJ mol 3 2800 KJ mol 2 5481 1 KJ mol 1 4 3680 KJ mol

He and a gas X having the same volume diffuse through a porous partition is 15 and 30 seconds respectively The gas X can be H 02 CH4

3 For the reduction of NO ion in an aqueous solution E is 0 96 V Values of E for some metal ions are given below V aq 2e V s E 1 19V Fe aq 3e Fe s E 0 04 V Au aq 3e Au s E 1 40 V Hg2 aq 2e Hg 1 E 0 86 V The pair s of metal that is are oxidized by NO in aqueous solution is are A V and Hg B Hg and Fe C Fe and Au D Fe and V

4 All of the above CK003 38 The reaction 2A B P follows the mechanis 2A A fast A B P slow The order of the reaction is 1 1 5 2 3 3 1 4 2 CK004

CK0026 25 For a reaction A B products the rate of the reaction was doubled when the concentration of A was doubled the rate was again doubled when the concentration of both A B were doubled the order of the reaction with respect to A B are 1 1 1 2 2 0 3 1 0 4 0 1 CK0027 31 31 F

5 A swimmer coming out from a pool is covered with a film of water weighing about 80g How much heat must be suplied to evaporte this water Aap H 40 79 KJ mol 1 181 KJ 2 362 KJ 3 90 5 KJ 4 40 79 KJ

The order of the over all reaction is 1 2 2 1 3 1 4 The rate for the reaction 4 Zero CK0034 RCI NaOH aq ROH NaCl is given by ratek RC The rate of the reaction is 1 Doubled on doubling the concentration of NaOH 2 Halved on reducing the concentration of RCI to half 3 Decreased on increasing the temperature of reaction 4 Unaffected by increasing the temperature of the reaction CK0035

Enthaly of formation of H O is 68 Kcal Enthalpy of formation of OH ions Given 4H H 0 13 7 Kcal mol 54 3 Kcal mol 2 57 3 Kcal ma 4 20 1 Kcal ma

21 Choose which of column Il condition are applicable for Column l items Column II Column I A When P 0 PS B Single phase of substance C Vapour state q D Liquid state t o p Boyle s temperature q Temperature Tc Pressure Pc r Temperature Tc Pressure Pc s Z 1 t Z 1

al proposal aw of mass expression CK0025 Z W the 30 Consider the following reaction KCIO 6FeSO 3H SO KC1 3Fe SO 3H O Which of the statements regarding this reaction is incorrect 1 It is a complex reaction 2 It is a tenth order reaction 3 It is completed in several steps 4 Order of this reaction can be determined CAL VENETICE DES

The ratio of the difference in energy between the first and second Bohr orbit of H to that between the second and the third Bohr orbit is 1 1 2 2 1 3 3 4 9 4 27 5

Which of the following orbital diagram violates Hund s rule 2s 16 2s 1 2s 14 2s 12 2p 111 2p 111 2p 11 2p 111

CK0036 36 The rate law of the reaction A 2B product d P is given by dt excess the order of the reaction will be 3 2 1 Zero 2 1 4 3 K A B If A is taken in large

1 AH AE 3 AH AE 2 AH AE 4 None TH0037 35 For which change AHAE 1 H g g 2HI g 2 HCI 0 NaOH NaCl s H O 0 3 C s O g CO g 4 N g 3H g 2NH g Sessio TH0038

28 For a chemical reaction AB the rate of reaction doubles when the concentration of A is increased 8 times The order of reaction w r t A is 1 3 4 Zero 2 2 3 102

10 For the water gas reaction C s H O g 1 CO g H g The standard Gibb s energy of reaction at 1000 K is 8 1 KJ mol Value of equilibrium constant is 1 2 6 2 6 2 3 8 2 4 10 dissolution

CK0033 33 The hypothetical reaction A B 2AB follows the mechanism as given below 34 A A A fast A B AB B slow A BAB fast The order of the over all reaction is 1 2 2 1 3 1 The rate for the reaction 4 Zero CK0034 ZE 40

HYSICS CHEMISTRY BIOLOGY English En Consider the following statements i The process of converting a precipitate into colloidal sol is called peptization ii Collodion is a 4 solution of nitro cellulose in a mixture of alcohol and ether iii Clouds are aerosols having small droplets of water suspended in air B C D Only i ii Only i iii Only i ii iii

Consider the following equilibrium reactions X Y K 2 Y Z K 0 2 Equilibrium constant for the reaction X Z is 0 4 0 1 2 2 hr

50 If S for H Cl and HCl are 0 13 0 22 and 0 19 kJ K mol respectively The total standard entropy for the reaction in H Cl 2HCl is 1 30 JK mol 3 60 JK mol Ses 2 40 JK mol 4 20 JK mol TDO054

mol 4 16 g of methane was subjected to combus C in a bomb calorimeter system The teme the calorimeter system including water was rise by 0 5 C Heat of combustion of me constant pressure is Heat capacity lorimeter system is 17 7 KJ K 890 KJ 890 KJ 2 885 KJ 4 885 KJ e standard beats of formation of CH fol

ant on C 30 Heat of reaction for CO g 1 2O g CO g at constant V is 67 71 K cal at 17 C The heat of reaction at constant P at 17 C is 1 68 0 kCal 3 67 42 kCal 2 68 0 kCal 4 None TH0032

he A 26 31 Following mechanism has been proposed for a reaction 2A B D E C D me ler experimentally PSEUDO FIRST ORDER REACTION MECHANISM OF REACTION 27 CK0215 slow fast 1 3 KAP A B A C E The rate law expression for the reaction is KIA B 2 TK A B 4 r K AC CK0032 NODETABAS TARGET CHERRING

Two Liquids A and B were added to a container and the pressure exerted by the solution was fou nd to be greater than the individual vapour pressure of both A and B Then which of the given optio ns cannot be correct explanation of above case Options A and B may be perfectly immiscible A and B may form a minimum boiling azeotrope A and B may show positive deviation from Raoult s law must have greater mole fraction in vapour phase