Physical Chemistry Questions

In how many elements the last electron will have the following set of quantum numbers n 3 and 1 1 a 2 b 8 c 6 d 10

s theory Idea of elliptical orbits In order to explain the fine structure of spectral lines in the hydrogen spectrum Sommerfeld in 1915 extended Bohr s heory and proposed that i An electron moves around a positively charged nucleus in different elliptical orbits in addition to circular orbits

The density of vanadium is 5 96 g cm Convert the density to SI units of kg m

26 Among the following the state function s is are 2009 a internal energy b irreversible expansion work c reversible expansion work d molar enthalpy

For the formation of 3 65 g of HCI gas what volume of hydrogen gas and chlorine gas are required at NTP conditions 1 1 L 1 L 3 3 651 1831 2 1 12 L 2 24 L 11211121 48

51 For a first order reaction rate constant is given as log K 14 1 2x104 T 9 then what will be value of temperature if its half life period is 6 93 x 10 3 min 1 100 K 3 720 K 2 1000 K 4 327 K

Find the concentration of H after mixing 20 ml 0 1M CH COOH and 10 ml 0 1 M NaOH Given K for CH COOH 1 7 x 10 5 a 2 3 4 x10 5 4 1 7 x 10 4 1 1 7 x 10 5 3 3 4 x 10 6

70 71 At any instant a rolling body may be considered to be in pure rotation about an axis through the point of contact This axis is translating forward with speed CBSE AIPMT 1989 a equal to centre of mass b zero c twice of centre of mass the above

to the same princip levels have different eccentricity More is the eccentricity of a subshell more is the opportunity of the electrons residing in that subshell to be closer to the nucleus Thus the subshell will posses more penetration power and the corresponding electrons belonging to the subshell will have more power to shield the nuclear charge

6 HY is a weak acid K 105 It forms a salt NaX 0 1M on reacting with caustic soda The degree of hydrolysis of NaX is How nin 2004 1M a 0 01 b 0 0001 c 0 1 d 0 5

7 11 50 ml of 0 5 N HCN is mixed with 50 ml of 0 5 N KOH If pK for HCN is taken as 6 then the pH of the resulting solution will be 1 7 0 42 9 7 6

21 What nature of electron is indicated by each of th following properties shown by electrons DAUG i Electron has mass 100x1 ii Electron possesses kinetic energy MOD iii Electrons can be polarised iv Electrons can be diffracted to ma

The bond dissociation enthalpies of H g and N g are 435 95 kJ mol and 941 8 kJ mol and enthalpy of 46 024 kJ mol 1 What is the formation of NH3 g is enthalpy of atomization of NH3 g a 0 170 MJ mol 1 c 1 170 MJ mol 1 b 1 70 MJ mol 1 d 2 130 MJ mol 1 faitric acid th

0 25 2 5 Calculate a molality b molarity and c mole fraction of KI if the density of 20 mass mass aqueous KI is 1 202 g mL

th When an electron of hydrogen atom jumps from n orbit to n th orbit let the frequency of emitted radiation be v According to Bohr s theory hv En E y or or or or 1 y 2 m 4 n h 27 me h n n 2 m 4 2 25 1 2 1 2 h3 n n 2 m 1 h 1 n n 2 m 4 1 1 ch3 n n V R 27 me 1 1 ch3 n n 1 1 n n 2 m 4 n h for H Z 1 9 1 wavelength of emitted radi ation and c velocity of light 10 R is a constant known as Rydberg s constant 27 me4 wave number 11

3 8 mol The number of mole of N atom in 18 066 x 1023 nitrogen atoms is 1 1 mol 2 2 mol 3 3 mol 4 4 mol

49 The boiling point of an aqueous solution of a non Im volatile solute is 100 15 C What is the freezing good point of an aqueous solution obtained by diluting the above solution with an equal volume of water The values of K and K for water are 0 512 and 1 86 K molality b 1 0 544 C 3 0 272 C 2 0 512 C 4 1 86 C

3 Which one of the following condition will favour forward process in the given reaction N g 3H g 2NH g ArH 0 1 High temperature and high pressure 2 Low temperature and high pressure 3 High temperature and low pressure 4 Low temperaturn

For given reaction to notebolzeic 2B A2B A er to d If Keq of reaction is 15 2 and E A 2 A 0 34V Then calculate E B B will be HET INCOT 1 0 80 2 0 80 3 1 27 no 2

Pressure is determined as force per unit area of the surface The SI unit of pressure pascal is 1 Pa 1 Nm 2 If mass of air at sea level is 1034 g cm2 calculate the pressure in pascal

2 Which is correct for gases showing attraction behaviour 1 3 dV dPr T 0 d PV dP T 0 2 d dP PV 0 T 4 All of these

0 05 M NaOH solution offered a resistance of 31 6 ohm in a conductivity cell at 298 K If t cell constant is 0 367 cm calculate its molar conductance

For the hypothetical reaction A g B g 2AB g A G and A S are 20 kJ mol and 20 JK mol respectively at 200 K If A Cp is 20 JK mol then A H at 400 K is a 20 kJ mol b 7 98 kJ mol c 28 kJ mol Revisie d None of these

The osmotic pressure of 0 5 M aqueous solution of CH COOH having 2pH at temperature T is A 0 051 RT C 1 02 RT 0 51 RT D 0 102 RT

0 15 g of an organic compound gave 0 12 g of silver bromide by carius method Percentage of bromine in the compound is b d a 20 02 c 34 04 40 6 54 04

Fig Average rate of V E 1 The decomposition of N O in CCl4 at 318K has been studied by monitoring the concentration of N O in the solution Initially the concentration of N O is 2 33 moll and after 184 minutes it is reduced to 2 08 moll The reaction takes place the equation according to 2N O g 4NO g 0 8 Calculate the average rate of this reaction in terms of minutes What is the rate of production of NO during the period Sol A N 0 At Rate 6 79x10 It may be understand that 1 A NO 4 At 1 Average 1 2 08 2 33 molL 1 2 molL min A NO A 184min rate 6 79 10 4 molL min 4x6 79x10 molL min

1 08 g of pure silver was converted into silver nitrate and its solution was taken in a beaker It was electrolysed using platinum cathode and silver anode 0 01 Faraday of electricity was passed using 0 15 volt above the decomposition potential of silver The silver content of the beaker after the above shall be a Og b 0 108 g

The Henry s law constant for solubility of gas A in water at 25 C is 10 atm The by volume of gas A 50 in gaseous mixture The number of moles of A dissolved in 100 mol of water at 10 atm pressure 298 K is A 5 104 B 10 x 104 C 5 10 D 10 x 10

In 1 L saturated solution of AgCIIK AgCl 1 6 x 10 01 0 1 mole of CUCI K CUCI 1 0 x 10 is added The resultant concentration of Ag in the solution is 1 6 x 10 The value of x is A 9 B 5 C 7 D 8

The radius of A is 66 pm and the radius of B is 140 pm Predict the probable co ordination number of A ions

5 4 Br Given Enthalpy of ionization of two acids AH HCN 4 52 kJmol 1 AH CH COOH 2 1 kJmol Which relationship for the two acids is true 1 PK HCN pK CH3COOH 2 pK HCN pK CH COOH 3 pK HCN pK CH COOH 4 pK HCN 2 1 452 pK CH3COOH

34 For the decomposition reaction NH COONH4 s 2NH3 g CO g the K Kp 2 9x105 atm The total pressure of gases at equilibrium when 1 0 mol of NH COONH 5 was taken to start with would be

8 The number of aluminium ions present in 54 g of aluminium atomic weight 27 is a 2 c 11 x 10 24 2014 I b 18 d 1 2 x 10 24

3 Determine the wavelength and frequency of the radiation having the longest wavelength in Lyman series of hydrogen atom R 109678 cm Ans Rydberg s equation R 11 In case of Lyman Ln n series n 1 n 2 or any other higher integral values 3 4 5 etc For the wavelength to be the longest the difference in energies between the two energy levels should be minimum Hence n 2

C Compound X has significant amount of enol Y X racemises during enolisation X can be 1 2 shift CI 1 0 HC HC C CH O to CH3 CH C H 5 Due H CIO CH3 1 CH CN CN B Xoor D No change of CH C CH OCH bautomer No shift

Bleaching powder reacts with iodide ion according to the following unbalanced equation OCI I H 1 Cl H O A 0 6000 g sample of bleaching powder requires 35 24 mL of 0 1084 N Na S2O3 to titrate the liberated iodine The percentage of Cl in the sample is a 22 58 Cl c 11 29 Cl b 5 15 Cl d 45 16 Cl

When the electron moves in an elliptical orbit the nucleus remains at one of the foci

Identify the spectral line having wavelength of 4 863 x 10 5cm in the emission spectra of hydrogen

If the density of methanol is 0 8 kgL what is the volume needed for making 2 5 L of its 0 4 M solution 1 0 4 L S 3 0 04 L 2 4 0 L D 4 40 L

53 Stacking of square close packed layers give rise to a bcc structure c Simple cubic structure pol close packed hcp structure of spheres the fraction of the volume occupied by when it will b fcc structure d hcp structure give dcc nepoz b co

A stationary mass of gas is compressed without friction from an initial state of 0 3 m and 0 105 M Pa to a final state of 0 15 m and 0 105 M Pa The pressure remaining constant During the process there is a transfer of 37 6 kJ of heat from the system During the process the amount of internal energy change is a 28 85 kJ c 21 85 MJ b 21 85 kJ d 53 35 kJ

Calculate molality of the solution obtained 2 0 3 m 3 0 2m Density of 2 03 M aqueous solution of acetic acid is 1 017 g mL molecular mass of acetic acid is 60 C the molality of solution 127 3 3 27 4 4 27

64 Among the following 1 Electron 2 Proton 3 a particle C ratio is minimum for 4 Neutron 65 Among the following which has maximum number of molecules 1 49 g of H PO4 3 28 g N 2 45 g of C6H12O6 4 36 g H O

23 The reversible expansion ob an ideal gas under adiabatic and isothermal conditions is shown in the figure Which of the following statement s is are correct 2012 Const a T 1 b T T c W P 0 V T isothermal W Isothermal Adiabatic adiabatic V P2 V2 T2 03 V3 T3

Considering the following ionisation steps A g A g e AH 100 eV A g A g e AH 250 eV Select the correct statements A IE of A g is 100 eV B IE of A g is 150 eV C IE of A g is 150 eV D IE of A g is 250 eV

Electrolysis of aq CuSO4 causes 1 An increase in pH 2 A decrease in pH 3 Either decrease or increase 4 None

If a stands for the edge length of the cubic sys tems simple cubic body centred cubic and face centred cubic then the ratio of radii of the spheres in these system will be respectively 1 1 a 3a 2 3 la 3a 2 a 3 2 2 1 3 2 a 2 1 3 4 a 1 a 2

4 04 A d 4 50 A 105 CsBr has bcc type structure with edge length 4 3 pm The shortest inter ionic distance between Cs and Br is a 3 72 pm b 1 86 pm c 7 44 pm d 4 3 pm

For gas A in a calorimeter heat evolved is 250 kJ mol For 0 2 mol of A temperature rise from 298 K to 300 K Find out heat capacity of calorimeter 1 12 5 kJ K 3 50 kJ K 2 25 kJ K 4 100 kJ K

Thomas Andrews plotted the P V curve for CO2 He plotted the isotherms of CO at various temperatures Later on it was found that real gases behave in the same manner as CO2 Andrews noticed that at high temp isotherms look like that of an ideal gas and cannot be liquified even at very high pressure As temp is lowered shape of curve changes from ideal behaviour 1 Sol 2 Sol P 70 C 50 C 30 C 20 C 13 C V The critical temp of gases A B C and D are 126 K 154 3 K 304 15 K 405 K respectively which gas shown greater deviation from ideal behaviour with increase in pressure A A C C B B D D D The compressibility factor of a van der Waal s gas at its critical point is A 1 B 0 375 C 2 67 D 0 48 B