Physical Chemistry Questions

A gas is allowed to expand in E well insulated container against a constant external pressure of 2 5 atm from an initial volume of 2 50 L to a final volume of 4 50 L The change in internal energy AU of the gas in joules will be 1 500 J 2 505 J 3 505 J 4 1136 25 J For 1 molal aqueous solution of the following compounds which one will show the highest freezing point

6 Given EC 0 7 Cr Based on the data given above strongest oxidizing agent will be EC Cr 0 74 1 CI 2 Mn AIEEE 2012 V EMnO Mn 1 51 V 2 3 1 33 V ECC 1 36 V Cr Cr 2 Cr

The empty space in HCP unit cell is 2 47 6 1 74 3 32 The correct statement s regarding defects in solids is are 4 26 JEE 2 JEE 2 and anion

4 1 5 10 1 The rate of a first order reaction is 0 04 molers at 01 min and 0 03 moles at 0 2 min after start of reaction The rate constant of the reaction is in min approximately 1 1 2 2 91 313 oxy 003 K 9 catalyst lowers the energy of activatio by 25 12 2 9x10 3 10 3 4 1 5 10 20 04 mole 10 2 mole 2 2 3 3 M 313 Mo 0 03 s 1 0 1 se 0502

3 Which one of the following statements is not true about the effect of an increase in temperature on the distribution of molecular speeds in a gas AIEEE 2005 a The area under the distribution curve remains the same as under the lower temperature b The distribution becomes broader c The fraction of the molecules with the most probable speed increases d The most probable speed increases

23 Which is the correct order of ionization energies 1 F F C Cl 2 F C Cr F 3 F C C F 4 F C F CL 104 If 23 33 1 F F C Cl 2 Exa c F 3 F C C F F d f at

A It is suspected that an acid base titration method has a significant indicator error and thus tends to give results with a positive systematic error i e a positive bias To test this an exactly 0 1 M solution of HCI is used to titrate 20 00 mL of an exactly 0 1 M solution of NaOH and the following results were obtained 20 06 20 18 19 87 20 51 20 34 20 41 Test for positive bias in these results at 95 confidence leve

Suppose that K is a proper subgroup of H and H is a proper subgroup of G If K 42 and G 420 And H has posible subgroups of orders 84 and 210 Does that mean that such subgroups actually exist Why or why not

Insert a few or the few whichever is suitable 1 2 3 4 It is a question of spending 5 6 In public libraries that we have are not well equipped days that are left to him he spends in solitude and meditatio days rest is all that is needed rupees Japanese that are in Mumbai are law abiding citizens words he expressed his gratitude to his friends Exercise 6 Fill in the blanks with a little or a few 1 There will be 2 I need 3 Could you buy 4 My parents give me 5 All we need is 6 Would like to eat 7 There is still 8 My friend knows rest rain this week bottles of water for me luck pocket money every week biscuits bread left celebrities

A 120 g sample of new wood has 21 8 mg of carbon 14 After a period of time there is now 5 45 mg of carbon 14 If the half life of carbon 14 is 5730 years how old is the wood now Select one O a 4 00 years b 22 900 years O c 5730 years d 5 50 years e 11 500 years

The ionization constant of benzoic acid is 6 46 x 10 5 and Kc for silver benzoate is 2 5 x 10 13 How many times silver benzoate is more soluble in a buffer of pH 3 19 as compared to its solubility in pure water 1 3 317 2 9 5 3 1000 4 7 5

Which of the following process is exothermic Na s Na g Na g Na g e C g CI g Cl g e Cl g

13 If initial concentration is reduced to 1 4 is 75 S in a zero 13 feffaf order reaction the time taken for half the reaction to complete is 1 75 S 2 150 S 3 50 S 4 37 5 S ukt 4x K x 75 xt XY 75ffa en tot m 1 75 S 2 150 S 3 50 S 4 37 5 S D 1 22 24 2 Table ld 75 c

If a solid PQ having NaCl type structure is heated so that the ions along one body diagonal are lost and trivalent ions R enter interstitial sites to maintain the electrical neutrality so that the new empirical formula unit is P Q R x y z are smallest possible integers The value of x y z is Q form the lattice

Ex 25 a Calculate the strength of 20 V of H O in terms of i normality ii grams per litre iii molarity and iv percentage b Calculate the volume strength of 3 58 N H O solution

The energy needed to remove one electron from unipositive ion is abbreviated as A 1st I P B 3rd I P D 1st E A 2nd 1 P The radius of pati

37 For the first order reaction 1 Degree of dissociation equals to 1 ekt 2 A straight line is obtained by the graph between reciprocal of conc and time 3 Time take of 75 completion of the reaction is three times of t 2 4 Dimension of pre exponenational factor in Arrhenious equation is T 37 4 16 da 1 fari 2 atat teffen fag a El 1 ek fic ad de 844 F 42 4G Y FATE M 3 3 75 1 2 44 ya 4 right pics at fault T

4 15 The sub shell that comes after f sub sell is called g subshell The number of g sub orbitals in g sub shell and the total number of orbitals in the principal orbital respectively are Final Results 0 10 and 25

2 XX e X g AH 720kJ mol g Calculate the amount of energy required to convert 110 mg of X atom in gaseous state into X ion Atomic wt for X 7 g mol 1 10 4 kJ 3 11 3 kJ 1 720 113 2 12 3 kJ 4 14 5 KJ 752 MAJKI 22 X 9 110 mg X ufafdd e AH 720kJ mot at the fy n Atomic wt for X 7 g mol 1 10 4 kJ 3 11 3 kJ 2 12 3 kJ 4 14 5 k 110 X10 7

46 An element X has the following isotopic composition 200 X 90 X 8 0 2X 2 0 The weighted average atomic mass of the naturally occurring element X is closest to 1 204 amu 4 200 amu 2 198 amu 3 197 amy

Determine the cell potential of an electrochemical cell based on the following two half reactions Oxidation Ni s Ni2 aq 2 0 M 2e Reduction VO aq 0 010 M 2H aq 1 0 M e VO2 aq 2 0 M H O 1

The heat of neutralization will be highest for which of the following neutralization reactions 1 NH OH and HCI 2 NH OH and CH COOH 4 NaOH and CH COOH 3 NaOH and HCI What is true about rate of reaction 1 Decreases with increase in temperature

Problem 7 1 The value of AG for the phosphorylation of glucose in glycolysis is 13 8 kJ mol Find the value of K at 298 K Solution AG 13 8 kJ mol 13 8 x 10 J mol Also AG RT InK Hence In K 13 8 x 10 J mol 8 314 J mol K x 298 K In K 5 569 K e 5 569

CO O CO AH Y 1 X Y 2 X Y 3 Y 2X 4 2X Y Calculate the standard potential of the cell if the standard electrode potential Zn Zn and Ag Ag are 0 763 V and 0 799V respectively 1 0 036V 2 1 56V 3 1 562V 4 0 799V

Which of the following transformation least energy is required 1 Fg F g e 2 Pg P g e 3 S g S g e 4 Clg Cl g e B CNOP PH3

4 dic quis ant faut T equation is T d 38 For an exothermic reaction following two steps are 38 fait fuffo fa fafed involved Step 1 A B I Step 2 I AB Which of the following graphs correctly represent this reaction 1 A B Reaction coordinate AB im imium im A B Reaction coordinate AB 4 A B A B In Arrhenious AB slow fast Reaction coordinate Reaction coordinate Step 1 Step 2 AB A B I I AB A B Potential energy JA A B AB Reaction coordinate AB Reaction coordinate EFTAT 1 as weit wegd all Reaction coordinate k A B AB Reaction coordinate

For pure water which of the following condition is valid at al temperature pH 7 pH pOH 14 pH pkw 2 pH pOH 7

300 The heat of combustion of ethyl alcohol is Kcal if the heat of formation of CO2 g and H O l are 100 Kcal and 50 Kcal respectively then heat of formation of ethyl alcohol is Question Type Single Correct Type 1 2 3 100 K cal 50 K cal 150 K cal

tion Compound Metallurgy Chemical Kinetics Periodic Table Spartan Batch 2NH3 g 22 kcal E for the 9 N g 3H g 2NH g 22 kcal fish fell E4 70 kcal 13 34folg is A For N g 3H g reaction is 70 kcal Hence the activation energy for 2NH3 9 1 92 kcal 2 70 kcal 3 48 kcal 4 22 kcal N g 3H g is reaction A 2NH g N g 3H g 1 92 kcal 2 70 kcal 3 48 kcal 4 22 kcal 10 fufchen w fazin afsu n JC

47 Relative stabilities of the following order CH3O CH3 III 1 I II III NV 3 N II III I I CH CH II CH3CH2 IV 2 N III II I 4 II N III I will b CH

Choose the correct or more suitable forms of the verbs to fill in the blanks 1 The train at 8 20 leaves is leaving 2 We to Hyderabad tomorrow go are going It is late I think I Who is arranging the party Mohan 3 4 5 Tea or coffee 1 6 1 7 The boat is full of water It to bed now will go am going it is going to do will do coffee will have am going to have to Delhi at this time tomorrow am flying will be flying will sink is going to sink

Which of the following is correct AC and A represent conductance at C concentration and at infinite dilution respectively AHCI A AC CI H ANNO AHNO Naci Ac 3 C ANaNO ANO A ac Ad HNO3 C

3 48 kcal 4 22 kcal 10 Observe the following reaction A g 3B g 2C g A dt The rate of this reaction min What is the value of 1 3 10 3 2 9 10 3 3 10 3 4 1 5 x 10 3 d B dt A 79 is 3 x 10 3 mol litre in mol litre min 1 92 kcal 2 70 kcal 3 48 kcal 4 22 kcal 10 for N g 3H g d B dt Fax a fa A g 3B g 2C g A dt 3 x 10 mol litre min sin al mol litre min 1 3 x 10 2 9x10 3 3 10 3 4 1 5 x 10 3

Q 1 30 100 Calculate the equilibrium pressure of gaseous mixture that results from the therm decomposition of ammonium chloride at 625 K according to the reaction given below NH4Cl s NH3 g HCl g Assume gaseous mixture behaves as an ideal gas at equilibrium Cp R A BT For NH4Cl s AH 1298K 314 430 kJ kmol AG 1298K 202 870 kJ kmol

Mg s Mg2 0 01M Ag 0 001 M Ag s If a current of 0 5 ampere flows through a water solution for 2 hours then how many lectrons would flow through the cell and how many cm of H is produced at 298 K MH 1 g mol Mo 16 g mol F 96500 C

SINGLE CORRECT QUESTIONS 1 Temperature of one mole of helium gas is increased by 1 C hence increases in internal energ A 7 cal B 5 cal C 3 5 cal D 3 cal Which has maximum internal onoray 2

1 Na K 2 K Rb 3 K Rb 4 Rb Na 4 A quantity of PC15 was heated in a 2 litre vessel at 525 K It dissociates as PCIs g PCI3 g Cl g At equilibrium 0 2 mol each of PCIs PCI and Cl is found in the reaction mixture The equilibr constant Kc for the reaction is 1 0 2 2 0 5 3 0 1 4 0 05

lass XIII Spartan Batch Chemical Kinetics GOC 31 In the following reaction A B C rate constant is 0 001 31 37ffshAB C fi 0 001 Ms A 1M 10 FAB Ms If we start with 1 M of A then conc of A and B after 10 minutes are respectively 1 0 5 M 0 5 M 2 0 6 M 0 4 M 3 0 4 M 0 6 M 4 None of these poslas 1 0 5 M 0 5 M 2 0 6 M 0 4 M 3 0 4 M 0 6 M 4 00001 0 Ti jop 0 4 7 99 0

A buffer solution is prepared in which the concentration of NH3 is 0 3 M and the concentration of NH is 0 20 M If the equilibrium constant K for NH3 equals 1 8x10 5 what is the pH of this solution 1 9 43 2 11 72 3 8 73 4 9 08

5 a The wavelength in a vacuum of electromagnetic radiation is 275 nm What is the frequency of this radiation b What is the energy in joules of a photon in air of radiation with a wavelength of 589 nm h 6 626 x 10 4 Js c 2 998 x 108 m sl

Na Process Na Naj A In 1 energy released II energy absorbed In both I and II energy is released B In both 1 and II energy is absorbed D In 1 energy absorbed II energy released

17 Which of the following solutions would be expected to be the best conductor of an electric current at room temperature 1 Point 0 10 M Na2SO4 1 0 M CH3COOH 0 10 M NaCl 0 10 M CO NH2 2 0 10 M CH3COOH

48 A zero order reaction A Product with an initial concentration A has a half life of 0 2 s If one starts with the concentration 2 A o then the half life is a 0 1 s b 0 4 s c 0 2 s d 08s

26 For a reaction A 3B Product Rate d A dt 26 k A 2 B the expression for the rate of reaction in terms of change in the concentration of B d B dt will be 1 k A B 2 k A 3B A 3B pro d A at 3 3k A B 4 1 3 k A B G K A B B 903 dt 3A 3B A B B 1 k A B 2 k A 3B 3 3k A B 4 1 3 k A B Chemical Kinetics GOC 32414 a falu d A dt d B dt 927 Rate of d das at dos 3 1

5 The freezing point of an aqueous saturated solution of I is 0 0024 C More than this can dissolve in a KI solution because of the following equilibrium 12 aq aq 13 09 0 1 M KI solution dissolves 12 5 g L of I Calculate the equilibrium constant K for the above equilibrium Also calculate the freezing point of the resulting solution Assume molarity to be equal to molality and also assume that conc of L in all saturated solutions is same K for water 1 86 K kg mol

3 RCI RBr RF RI 4 RI RBr RCI RF Identify the correct order of boiling points of the following compounds I CH CH CH CH OH II CH CHCH CHO III CH CH CH COOH 1 I II III 2 III I II 3 I III II 4 III II I HgCl and 12 both when dissolved in water containing I ions the pair of species formed is 1 HgI2 I 3 Hg 1 1 4 Hgl I 2 Hgl

1 3 3 3 Trimethyl 1 propene 3 3 3 Dimethyl 1 butene 3 A solution of metal hydroxide MOH with copper sulphate and mixed tartarate of metal M with another metal M of the same group is used in the detection of CHO group Metal M and M are respectively 1 Na K 2 K Rb 3 K Rb 4 Rb Na A quantity of PC15 was heated in a 2 litre vessel at 525 K It dissociates as 4 2 1 1 1 Trimethyl 2 propene 4 2 2 Dimethyl 3 butene

O Which of the following is correct AC and represent conductance at C concentration and a infinite dilution respectively ANCI AC AC CI H ANaNO3 HNO Naci Anci C ANaNO3 ANO A ac ACI HNO3 ACH COOH 4 CH3COO 4 H

A 150 mL aqueous solution containing two dissolved sodium salts namely sodium sulfate with a density of 2 66 g mL and sodium chloride with a density of 2 16 g mL was produced by a student The concentrations of the solutes in 150 ml of solution were 4 w v and 10 w w respectively To complete the experiment performed by the student calculate for the following A Mole fraction of the solute with the higher number of moles B Molarity of the solution if it contains ONLY the solute with the higher number of moles C Molality of the solution that you have computed in letter B and D Normality of the solution that you have computed in letter B Molecular weights Sodium chloride 58 443 g mol Sodium sulfate 142 04 g mol Water 18 01528 g mol ANSWER THE FF A Mole fraction of the solute with the higher number of moles B Molarity of the solution if it contains ONLY the solute with the higher number of moles C Molality of the solution that you have computed in letter B D Normality of the solution that you have con omputed in lottor B

d 40 The rate of disappearance of Cr Oion at any instant in 40 f3ffl 4 a el c the following reaction Cr O 61 14H 2Cr 31 7H O is 1 55 x 10 2 mol L s The rate of formation of iodine is 1 9 3x10 2Ms 1 2 4 65 x 10 2 MS 1 3 5 0x10 Ms 1 4 250x10 Ms 1 conce of catalyst causes the activation Cr O3 61 14H 2Cr 31 7H O 1 55 x 10 mol L s 1 1 9 3x10 2Ms 2 4 65 x 10 2Ms 1 3 5 0x10 Ms 42 50 x 10 Ms 1 22 ritch and sufferfata uch fufh4 enor 188802 812 4 3r vers