Physical Chemistry Questions

s of an ideal gas at 200 K is compressed reversibly and adiabatically untill final temperature reaches 250 K If molar heat capacity at constant e is 27 cal mol K find work 50 cal 550 cal 050 cal

d 3 84x10 m The wavelength of radiation emitted when electron falls from 4th Bohr s orbit to 2nd in H atom is RH 1 09678x10 7m a 972 nm c 243 nm 5 The energy of electron 486 nm d 182 nm

If bond dissociation energy of H Cl and HC1 is 10 20 and 60 kcal mol respectively then what is the enthalpy of formation of HCI kcal mol 0 45 O 45 0 90 O 90 kcal mol kcal mol kcal mol

In which of the following arrangements the sequence is not strictly according to the property written against it A B C D CO SiO SnO PbO increasing oxidising power NH3 PH3 AsH3 SbH3 increasing basic strength HF HCI HBr HI increasing acidic strength B C O N increasing first ionisation enthalpy

Electron gain enthalpy with negative sign of fluorine is less than that of chlorine due to A B High ionization enthalpy of fluorine D Smaller size of chlorine atom C Smaller size of fluorine atom Bigger size of 2P orbital of fluorine

0 7 grams of Na2CO3 xH O were dissolved in water and the volume was made to 100 mL 20 mL of this solution required 19 8 mL of N 10 HCI for complete neutralization The value of x is Report your answer by rounding it up to nearest whole number

The heat of combustion of carbon to CO is 393 5 KJ mol The heat released upon the formation of 35 2 g of CO from carbon and oxygen gas is ne ch 1 315 KJ of 2 315 KJ 3 630 KJ an 4 630 KJ

t Considering the state of hybridization of carbon atoms find out the molecules among the following which is linear 1 CH3 C C CH3 2 CH CH CH C CH 3 CH3 CH CH CH3 4 CH CH CH CH

2 Flame photometers use as detectors a phototubes c photovoltaic cells e The intensity of spectral lines b photomultiplier tubes d photoconductors in different parts of the flame 5 come

g and pentane g respectively The value of Excell pentane oxygen fuel cell is 1 1 968 V 2 2 0968 V 3 1 0968 V 4 0 0968 V approximately log 4 0 60 log 5 0 69 1 50 min 2 45 min 3 60 min 4 40 min 2 21 3 mg 3 24 3 mg 4 13 6 mg Contact Number 9667591930 8527521718 for the 127 In producing chlorine through electrolysis 100 W power at 125 V is being consumed How much chlorine per min is liberated ECE of chlorine is 0 367x10 6 kg C 1 17 6 mg 128 A solution containing 10g per dm of urea molecular mass 60g mol is isotonic with a 5 solution of a non volatile solute The molecular mass of this non volatile solute is 1 25g mol 2 300g mol 3 350g mol 4 200g mol 129 For the reaction 2A B 3C D Which of the following does not express the reaction rate 1 d C 3 dt 126 If 60 of a first order reaction was completed in 60 min 1 00 g of non electrolyte solute molar mass 250 mol was dissolved in 51 2 g of benzene If the freezing point 50 of the same reaction would be completed in depression constant K of benzene is 5 12 mol the freezing point of benzene will be lowered by 1 0 4 K 2 0 3 K 3 0 5 K 4 0 2 K 2 3 4 130 d D de d B dt d A 2dt 131 During osmosis flow of water through a semi permeable membrane is 1 from solution having higher concentration only 2 from both sides of semi permeable membrane with equal flow rates 3 from both sides of semi permeable membrane with unequal flow rates 4 from solution having lower concentration only 132 A compound is formed by cation C and anion A The anions form hexagonal close packed hcp lattice and the cations occupy 75 of octahedral voids The formula of the compound is 1 CA3 133 2 C A3 3 C3A 4 C3A4 Following limiting molar conductivities are given as H SO4 K SO4 y Scm mol 1 x Scm mol 1

The zone refining of metal is based on the principle of Question Type Single Correct Type 1 Greater mobility of pure metal than that of impurity 2 Higher melting point of the impurity than that of the pure metal 3 Greater noble character of the solid metal than that of the impurity 4 Greater solubility of the impurity in the molten state than in the solid

A 50 by 50 cm square vertical plate is maintained at 95 C and exposed to saturate steam at 1 atm pressure Calculate the amount of steam condensed per hour Calculate the ate of ond 1

SolveLancer Test How many of the following Lattice systems will have all sides equal 2 Tetragonal 3 Rhombohedral 4 Cubic SolveLancer Tem 1 Triclinic a 1 and 2 b 2 and 3 c 3 and 4 d 1 and 4

A 40 by 40 cm plate is inclined at an angle of 30 with the vertical and exposed to water vapor at 1 atm The plate is maintained at 98 C Calculate the heat transfer and mass flow rate of condensate

3 Calculate the standard enthalpy of formation of naphthalene C10H8 when the standard enthalpy of combustion of naphthalene is 5153 kJ and the standard enthalpies of formation of CO2 and H2O are 393 5 kJ mol 1 and 285 8 kJ mol 1 respectively

An equilibrium mixture in a vessel of capacity 100 litre contain 1 mol N 2 mol O2 and 3 mol NO Find number of moles of O2 to be added so that at new equilibrium the concentration of NO is 0 04 mol lit A B 101 18 Correct Answer 101 9 202 9

A sample of water has a hardness expressed as 80 ppm of Ca This sample is passed through an ion exchange column and the Ca is replaced by H What is the pH of the water after it has been so treated Atomic mass of Ca 40 1 3 2 2 7 3 5 4 4 2 4

A certain liquid has a vapor pressure of 92 0 Torr at 23 0 C and 338 0 Torr at 45 0 C Calculate the value of AHp for this liquid AH 72 Incorrect Calculate the normal boiling point of this liquid boiling point Incorrect A 0 513 g sample of steam at 107 5 C is condensed into a container with 5 01 g of water at 15 2 C What is the final temperature of the water mixture if no heat is lost The specific heat of water is 4 18 the specific heat of steam is 2 01 C and AHp 40 7 kJ mol kJ mc C

The enthalpy of neutralization of HCN by NaOH is 12 13 kJ mol The enthalpy of ionisation of HCN will be 1 45 07 kJ 2 4 310 kJ 3 451 9 kJ 4 33 77 kJ

SolveLancer Test With reference to aqua regia choose the correct option s A Hg Cl is soluble in aqua regia B Aqua regia is prepared by mixing conc HCl and conc HNO3 in 1 3 v v ratio C Reaction of gold with aqua regia produces an anion having Au in 3 oxidation state D Aqua regia employed for etching of glass SolveLancer Test a Only A b Both B C c Both A D d A C D

Which of the following statements about an ideal gas is incorrect The average kinetic energy of an ideal gas decreases when temperature increases O The pressure of an ideal gas will decrease when the volume is increased at constant temperature The molecules in an ideal gas are in constant random motion O The volume of an ideal gas will increase when the temperature is increased at constant pressure O A gas behaves ideally when the distance between gas molecules is large compared to the size of the molecule

4 Zero 113 A catalyst lowers the activation energy of a reaction from 20 kJ mole to 10 kJ mole The temperature at which the uncatalysed reaction will have the same rate as that of the catalysed at 27 C is 1 123 C 2 327 C 3 327 C 4 23 C

A certain mixture of HCI and CH3 COOH is 0 1 M in each of the acids 20 ml of this solution is titrated against 0 1M NaOH By how many units does the pH change from the start to the stage when the HCI is almost completely neutralised Ka for acetic acid 1 8 x 10 6 1 2 03 2 0 775 3 2 325 4 3 172

When equal volumes of 0 2 M AgNO and 1 M KCN solutions were mixed then at equilibrium concentration of Agt was found to be 10 M While when equal volumes of 0 2 M Zn NO solution and of 1 M KCN solution were mixed then at equilibrium concentration of Zn ion was found to be 10 12 M Then find the equilibrium constant K of following reaction 2 Ag CN J aq Zn aq Zn CN aq 2Ag aq Consider two equilibrium 2CL g 2H O g 4HCI g O g and N g O g 2NO g

17 The freezing point in C of solution containing 0 1 g of K3 Fe CN 6 mol wt 329 in 100 g of water K 1 86K kg mol is 2 3 10 c 5 7x 10 3 Jas b 5 7 x 10 2 d 1 2x 10 2011

1 Problem about Nearly Free electron in One Dimension Electrons of mass m are confined to one dimension A weak periodic potential described by the Fourier series V x Vo Vi cos 2xx a V cos 4xx a is applied a Under what conditions will the nearly free electron approximation work Assuming that the condition is satisfied sketch the three lowest energy bands in the first Brillouin zone Number the energy bands starting from one at the lowest band b Calculate to first order the energy gap at k a between the first and second band and k 0 between the second and third band

Glycine C H5NO is an important amino acid found in high protein foods How many carbon atoms are there in 1 50 g of pure glycine Choose the closest answer O1 20 1022 atoms 03 01x1025 atoms O1 87X1023 atoms 06 78x10 5 atoms 241x10 atoms

Which solution would have the greatest buffering capacity Select one a 0 189 M HF and 0 103 M NaF Ob 1 15 M HF and 0 624 M NaF c 0 574 M HF and 0 312 M NaF d They are all buffer solutions and would all have the same capacity e 0 287 M HF and 0 156 M NaF X

The activation energies of the forward and backward reactions in the case of a chemical reaction are 30 5 and 45 4 kJ mol respectively The reaction is 1 Exothermic 2 Endothermic 3 Neither exothermic nor endothermic 4 Independent of temperature

8 In zinc blende structure which of the following statements is not correct a Zinc ions occupy half of the tetrahedral sites b Each Zn ion is surrounded by six sulphide ions c Each S ion is surrounded by six Zn ions d It has fcc structure

Which amongst the following compounds ii K PtCl3 C H4 iv Ti 0 C6H5 4 organometallic i Al2 CH3 6 iii N CH3 3 Question Type Single Correct Type 1 i only 2 iii and iv only 3 i ii and iii A i and ii only

3 The blue colour changes to brown on standing 4 In concentrated solution blue colour changes to bronze and becomes diamagnetic One mole of ethanol is produced reacting graphite H and O together The standard enthalpy formation is 277 7kJmol Calculate the standard enthalpy of the reaction when 4 moles of graph is involved 1 277 7kJ mol 2 555 4kJ mol 3 138 85kJ mol 4 69 42kJ mol

Use Hess s Law to calculate the enthalpy change for the reaction WO3 s 3H2 g W s 3H O g from the following data 2W s 302 g 2WO3 s AH 1785 4 kJ 2H2 g O2 g 2H O g AH 457 84 kJ A 252 9 kJ B 205 9 kJ O C 125 9 kJ D 364 9 kJ

Given i Cu 2e value ii Cu e 100 Electrode potential E for the reaction Cue Cu will be 1 0 52 V 2 0 90 V 3 0 30 V 0 201 Cu E 0 337 V Cu E 0 153 V

SolveLancer Test What is are characteristic of ozone O 1 The O O distances are not equivalent 2 It is a non linear triatomic system 3 It is made by passing an electrical discharge through oxygen 4 It is an extremely powerful oxidizing agent SolveLancer Test a 1 3 4 b 2 3 4 c 1 3

10 The dissolved oxygen in test solution shows interferring nuisance in polarographic analysis due to reaction of a oxidation of mercury c Oxidation of cations b conversion of O H O H O d H O O H O 02

SolveLancer Test In a given reaction A BC the percentage of B from A is 20 and percentage of C from B is 40 What is the overall percentage of C from A SolveLancer Test a 40 b 20 c 60 d 8

Consider that azimuthal quantum number 7 is having n 1 values i e whole number from o to n instead of 0 to n 1 value for any value of principle quantum number n If all the current laws of electronic configuration are applicable then what will be the spin only magnetic moment of Fe2 ion A 2 82 BM B 4 89 BM C 3 87 BM D 1 73 BM

The activation energies for forward and backward reaction in a chemical reaction are 20 5 and 55 5 kJ mol respectively The reaction is O Exothermic O Endothermic O Neither exothermic nor endothermic O Independent of temperature

The standard reduction potentials of Ag Cu Co and Zn are 0 799 0 337 0 277 0 762V respectively Which of the following cells will have maxiumum cell E M F 1 ZnZn 1M Cu 1M Cu 2 2 Zn Zn 1M Ag IM Ag 3 Cu Cu 1M 4g 1M Ag 4 ZnZn 1M Co 1M Co

11 If the total number of atoms per unit cell in an hcp structure and a bcc structure gets halved then ratio of percentage voids in hcp and bcc structures is 1 3 34 27 22 21 2 4 21 22 37 34

3 In Kjeldahl s method of estimation of nitrogen nitrogen is quantitatively converted to ammonium sulphate It is then treated with standard solution of alkali The nitrogen which is present is estimated as 1 N 2 NO 3 NH

ion 4 A flask of 2 dm capacity contains O at 101 325 kPa and 300 K The gas pressure is reduced to 0 1 Pa Assuming ideal behaviour answer the following i What will be the volume of the gas which is left behind ii What amount of O and the corresponding number of molecules are left behind in the

The mass of a piece of metal is 19 5061 grams When the piece of metal was dropped into a graduated cylinder that had an initial water volume of 8 75 cm the total volume was 9 76 cm What is the density of the piece of metal in g cm

PV value decreases with increase in P at constan temperature when a there is no attractive or repulsive forces between molecules b attractive and repulsive forces between molecule are equal c attractive forces between predominant d repulsive forces between predominant molecules ar molecules ar J K CET

of the following expressions is true 1 H CO g 1 AH CO2 g 2 1 2 AH CO g AH C graphite 2 1 3 AH CO g AH CO g AH 0 9 2 AH O2 g comb 4 AH CO g AH C graphite A Homb CO g

5 Magnesium oxalate when heated at temperature above 400 C shows a loss in weight due to evolution of a 0 b H O c CO 6 A compact sample will decompose at a d CO CO temperatura than a longa compla

A fused mixture of rubidium fluoride and uranium IV fluoride can be oxidized with fluorine t produce a uranium compound in which the uranium is mainly but not entirely in the oxidation states The product is found to contact 54 93 uranium A 1 0357 gm sample of t product immersed in 100 ml of 10 07 centimolar acidified potassium iodide solution reacti accordingly as following equation 21 2UF6 2UF4 1 4F The iodine produced was titrated with 14 80 ml of 14 94 centimolar sodium thiosulphate soluti What of the original mixture oxidized to 5 oxidation state

cell 31 In alkaline solution KMnO reacts as follows 2KMnO 2KOH 2K MnO H O O Therefore its equivalent weight will be 1 31 6 2 52 7 3 79 0 158 0 32 The equivalent weight of FeS in the following Oxidation Numbe agent and Reduc Oxidation num respectively 1 6 6 2 5 6 3 6 5 4 5 5

The PEC diagram to the right indicates the mixing behavior of A and B Based on the PEC diagram which of the following interactions are the STRONGEST I A A interactions II B B interactions III A B interactions PE UM II and III M C