Physical Chemistry Questions

The density of solid Ar RAM 40 is 1 68 g ml at 40 K If the argon atom is assumed to be a sphere of radius 1 5x 108 cm then what of solid Ar is apparently empty space N 6 10 A 35 64 B 64 36 C 74 D None of these

he equilibrium constant K for the following reaction at 700 K is 5 x 108 C H g Br g 2HBr og 1261 noiose1 If a mixture of 0 8 mol of H 0 3 mol of Br and 0 1 mole of HBr is heated at 700 K The amount of HBr at equilibrium is 1 0 2 mol 3 0 5 mol 2 0 3 mol Patron 4 4 0 7 mol 0 7 mol stinu of

A diatomic molecule has a dipole moment of 1 2 D If its bond length is equal to 10 m then the fraction of an electronic charge on each atom will be 1 42 2 52 70 en farfars fa 1 2 D 1 42 10 m mm 2 52

xSn yCr O7 2 zH In acidic medium dichromate ion oxidizes stannous ion as zH aSn 4 bCr H O where x y z a b and c are respective stoichiometric coefficients Determine the value of x y z a b

46 What is the dominant intermolecular force or bond that must be overcome in converting liquid CH OH to a gas a Dipole dipole interaction b Covalent bonds c London dispersion force d Hydrogen bonding 2009

Taking antilogs k antilog 1 9849 antilog 2 0151 1 035 x 10 s EXAMPLE 48 The rate of a particular reaction quadruples when the temperature changes from 293 to 313 K Calculate N C E R T Text book Problem the activation energy of the reaction R 8 314 JK mol

1 Arrange the following gases in the increasing order of b Give reason 02 CO H He ii Arrange the following gases in the decreasing order of magnitude of a Give reason CH4 0 H ns Molar volume occupied by the gas molecules size of the molecules and van der Waak constant b represents molar volume of the gas molecules Hence value of b increases in the following order TH H He O CO ii van der Waals constant a is the measure of magnitude of intermolecular attraction The magnitude of intermolecular attractions increases with increase in size of electron cloud in a molecule Hence for the given gases magnitude of a decreases in the following order CH4 O H Greater the size of electron cloud greater is the polarisability of the molecule and greater is the dispersion forces or London forces

Q 26 What is the product of the following reaction and which catalyst is used in the given reaction 2SO2 g O2 g 196 6K mol Max score 1 Neg score 0 SO3 V205 S202 ZnO SO CuBr2 4H

A glass cylinder 10 cm in diameter and 20 cm tall initially contains water vapor at 300 K and a pressure of 100 torr A liquid nitrogen cold finger 1 cm in diameter is placed against one face of the cylinder How long will it take for the pressure in the cylinder to drop to 10 5 torr

v many grams of CaSO 4 may be produced from 3 78 g of SO the mass of iron in g which will be converted into Fe 304 by the action of 18 g of steam t What is the value of W 7 Fe H 0 Fe3O4 H culate the total moles of atoms of each element present in 122 5 g of KClO 3 dissolving 2 0 g of metal in sulphuric acid 4 51 g of the metal sulphate was formed The ific heat of the metal is 0 057 cal g C What is the valency of the metal 1 gram of a metallic chloride was found to contain 0 835 g of chlorine Its vapour density is 5 If its molecular formula is M Cl then what is value of x y

1 SiF 2 ICI 3 SF 4 PCI In a closed packed arrangement A type of atoms are at corners B type of atoms are at face centres Ctype of atoms are at tetrahedral voids and D type of atoms are at octahedral Voids If all the atoms along any one body diagonal are removed then what will be formula of compound 1 AB C D 3 AB C D 2 AB C D 4 None of these 66 1 SiF 2 ICI falfifers A 3 SF O 1 AB C D 3 AB C D 4 PC VER A CR agenerata fuf sementa fuffet fa fam 2 AB C D 4

M 2 0g of polybasic organic acid Molecular mass 600 required 100 mL of a NaOH solution for complete neutralisation Find the basicity of acid A mixture contains 1 0 mole each of NaOH Na CO and NaHCO When half of mixture is titrated with HCl it required a mole of HCI in presence of phenolphthalein In another experiment half of mixture required y mole of same HCI in presence of methyl orange Find the value of x y When Bro ion reacts with Br ion in acidic medium Br is liberated Calculate the ratio of molecular mass and equivalent mass of KBRO A volume of 12 5ml of 0 05 M SeO reacts with 28ml of 0 1M CISO which is oxidised to To what oxidation state was the selenium converted by the reaction A02558 impure sample of copper ore is dissolved and Cu is titrated with KT solution L

ir is trapped in a horizontal glass tube by 36 cm mercury column as shown below 1 atm Hg 136 cm the tube is held vertical keeping the open end up length of air column shrink to 19 cm What the length in cm by which the mercury column shifts down Elask containing air at 107 C and 722 mm of Hg is cooled to 100 K and 760 mm of Hg If msity in the initial condition 1 g cm then what is the final density g cm an ideal gas at 100 K is heated to 109 K in a rigid container the pressure increases by X at is the value of X e van der Waal s constants for a gas are a 3 6 atm L mol 2 b 0 6 L mol If R 0 08 L K mol and the Boyle s temperature K is Tg of this gas then what is the value of T 15 ask has 10 gas particles out of which four particles are moving at 7 ms aining are moving at the same speed of X ms If the r m s of the gas is 5 ms value of Y and the what is

A 0 605 gm sample of Sodium Carbonate and Sodium bicarbonate the solution titrated with 0 106 N HCI 40 2 ml needed from the titrant to reach phenolphthalein and when titrated in presence of blue bromophenol found the total acid volume is 95 4 ml Calculate the for the constituents

The value of n 1 2 3 4 and 5 for the Lyman Balmer Paschen Brackett and Pfund series respectively n2 is greater than n by at least 1 Values of n and n2 for various series Spectral series Value of n 1 2 Lyman series Balmer series Paschen series Brackett series Value of n 2 3 4 5 3 4 5 6 4 5 6 7 4 5 6 7 8 Pfund series 5 6 7 8 9 Lyman series is observed in both absorption and emission spectrum of hydrogen Series Limit Last line of a spectrum is called the series limit Last line is also called the line of shortest wavelength and highest energy We know 3 Total six lines in the s Mathematical formula n n Viewed Balmer lines by the naked eye n 3 Ha first line Red 6563 n 2 Illuant n 4 HB second line Blue 4861 A n 2 Fig 2 19 Balmer se

1 25 x 10 1250 K T EXAMPLE 46 The decomposition of A into product has value of k as 4 5 x 103 s at 10 C and the energy of 60 kJ mol At what temperature could k be 1 5 x 104 N C E R T Text book Soluti

what will be formula of compound 1 AB C D 3 AB C D 2 AB C D 4 None of these If the rate constant K of a reaction is 1 16 x 10 mol L min the order of reaction is 1 0 2 1 3 2 4 cannot be determined 1 AB C D 3 AB C D 67 af 2 AB C D 4 1 0 2 1 3 2 4 fuiff frai K 1 6 x 10 L z fe rit 1

Li and potassium crystallizes in a body centred cubic lattice with their radii 152 and 230 pm respectively Find the volume occupied by 100 g Li metal in the solid state and the weight of solid potassium present in the volume equivalent to 100 g of Li metal

2 To coagulate Agl Ag NO Sol The decreasing order of coagulation power in following is al NaCl b K SO4 d K Fe CN c d 3 4 d c b c Ca PO4 2 2 d c b a 4 d c a b

Paragraph for Question Nos 26 and 27 10 5 g of a mixture containing P40 0 Na3PO4 and NaCl was dissolved in water and diluted to 250 cc In solution P 010 P4010 was hydrolysed completely to phosphoric acid H PO4 The resulting solution was analy volumetrically Atomic masses of P 31 Na 23 O 16 26 If 35 ml of above stock solution was titrated using 1 1 N NaOH solution 15 ml of base was requied to reach equivalance point Molarity of H PO4 in solution was approximately A 0 7 C 0 9 B 0 8 D 0 16

Given n 1 n 1 2rn where nth n 1 and n 1 th shell respectively Calculate the value of n The energy of separation of an electron is 30 6 eV moving in an orbit of Li 2 Find number of waves made by the electron in one complete revolution in the orbit Calculate the number of waves made by a Bohr electron in one complete revolution orbit of H atom if ratio of de Broglie wavelength associated with electron moving in n and 2nd orbit is 1 5 A certain dye absorbs lights of 2 400 nm and then fluorescence light of wavelength 5 Assuming that under given condition 40 of the absorbed energy is re emit fluorescence calculate the ratio of quanta absorbed to number of quanta emitted ou A photon of energy 4 5 eV strikes on a metal surface of work function 3 0 eV If uncerta

9 How many degenerate orbitals are present in a subshell if electron associated with that subshell possesses orbital angular momentum 2 3 1 No degenerate orbitals 2 Seven degenerate orbitals 3 Three degenerate orbitals 4 number of degenerate orbitals are same as in subshell which possesses u 3 46 B M wher colle to s two Ch

If the average molecular mass of air is 29 then assuming N and O gases are there which options are correct regarding composition of air i 75 by mass of N2 ii 75 by moles N2 iii 72 41 by mass of N A Only i is correct B only ii is correct C Both ii and iii are correct D both i and ii are correct

49 The correct order of increasing bond angles in the following triatomic species is a NO NO NO b NO NO NO c NO NO NO d NO NO NO 2008 5

1 Correct IUPAC name of the following compound is 1 4 1 1 dimethylethyl 5 ethyloctane 2 5 ethyl 4 1 1 dimethylethyl octane 3 5 1 1 dimethylethyl 4 ethyloctane

A solution of A is made to React with chlori ne water in the presence of carbon tetrachlo ride On shaking the carbon tetrachloride lay er is found to be orange in colour Identify c ompound A Write the chemical equation for the reaction Also name the type of chemica I reaction

Q 27 The magnitude of surface tension of liquid depends on the attractive forces between the molecules Arrange the following in increasing order of surface tension Dy Water alcohol C H5OH and hexane CH3 CH 4 CH3

133 The value of equilibrium constant of the reaction HI g H g 1 is 8 Then find equilibrium constant of the reaction H g 1 9 2HI g 1 3 18 2 16 4 1 16

Identify the wrong statement from following about Ellingham diagram 2 It tells about the stability of oxide 1 It gives rate of reaction Re 3 It gives idea about reduction of metal oxide 4 It gives idea about free energy of reduction 6 1 Ellingham diagram do not gives any idea about rate of reaction rest all statement are correct renc

The temperature of equal masses of three different liquids A B and C is 12 18 and 28 C respectively When A and B are mixed the temperature is 16 C When B and C are mixed it is 23 C Selected correct statements

Cr3 To what oxidation state was the selenium converted by the reaction A 0 276g impure sample of copper ore is dissolved and Cu2 is titrated with KI solution 1 liberated required 40 mL of 0 1 M Na S O3 solution for titration What is the of impurities in the ore A sample of 28 mL of H O aq solution required 10 mL of 0 1M KMnO4 aq solution for complete reaction in acidic medium What is the volume strength of H O For the redox reaction given below what is the value of Z XNO y As S3 2H O AsO NO SO2 H On heating 0220 g of a metallic oxide in presence of hydrogen 0 045 g of water is formed If

4 n 3 1 m 1 s 2 How much volume of 5M HNO is required to oxidise 16 g Fe if HNO is converting into NO 1 16 ml 2 19 05 ml 4 32 ml 3 38 1 ml The compound X C H reacts with ammonical AgNO to give a white precipitate and reacts with 52 53 4 n 3 f 1 m 1 s 16 Fe ffe SM HN A SIRA Safe HNO NO uftenta ar 12 1 16 ml 3 38 1 ml 2 19 05 ml 4 32 ml X C H if AgNO fa K

For the reaction 2HI g H g 1 g The degree of dissociation a of HI g is related to equilibrium constant Kp by the expression Question Type Single Correct Type 1 2 1 2 Kp 2 1 2Kp 2 2Kp

What volume of a liquid in L will contain 10 mole If molar mass of liquid density is 1 4g mL 16 g of SO gas occupies 5 6L at 1 atm and 273 K What will be the value of 200 mL of 1M HCl is mixed with 300 mL of 6 M HCl and the final solution 1000 mL Calculate molar concentration of H ion w boots N g reacts with H g in either of the following ways depending upon supp

The edge length of solid NaCl is 563 8 pm and its density is 2 165 g cc Calculate apparent molecular weight of NaCl The difference between the value calculated and the accurate molecular weight is ascribed to a type of crystal defect in which Na atom replaces a number of Nations and equal numbers of anionic sites remain vacant Calculate the percentage of anions site that are vacant

Calculate your specific activity based on 3H 5 x 10 15 abundance 14C 1 2 x 10 10 abundance and 40K 1 17 x 10 3 abundance Assume you are 23 2 carbon 11 6 hydrogen and 0 35 potassium by weight 2 points

A mixture of N and H is caused to react in a closed container to form NH3 The reaction ceases before either reactant has been totally consumed At this stage 2 moles each of N H and NH3 are present Then the weight of N and H present originally were respectively 1 112 g and 8 g 3 84 g and 8 g 2 84 g and 10 g 4 112 g and 10 g

4 0 8 If enthalpy of neutralisation of HCI by NaOH is 57 kJ mol and with NH4OH is 50 kJ mol Calculate enthalpy of ionisation of NH4OH aq Lattice energy of NaCl s is 790 kJ mol 1 and enthalpy of hydration is 785 kJ mol Calculate enthalpy of solution of NaCl s xg sample of NH4NO3 is decomposed in a Bomb calorimeter The temperature of calorimeter increase by 4 C The heat capacity of the system is 1 25 kJ C Calculate the value of x Given molar heat of decomposition of NH4NO at constant volume is 400 kJ mol A heat engine operating between 227 C and 77 C absorbs 10 kcal of heat from the 227 C reservoir reversibly per cycle Calculate total work done in kcal in two cycles In ahamical reaction in kcal

In the Arrhenius equation for a certain reaction the value of A and E activation energy are 4 10 3 s and 98 6 kJ mol respectively If the reaction is of first order at what temperature its half life period be ten minutes Ans 311 35 K

3 An atomic solid crystallizes in a body centre cubic lattice and the inner surface of the atoms at the adjacent corners are separated by 40 pm If the atomic weight of A is 7 calculate the density of solid

one of the properties of a solution is that A solution is always transparent in nature then why are alloys called solution i mean they are not transparent in nature for example brass is not transparent

1 mole of ferric oxalate Fe2 C2O4 3 is oxidised by x mole of MnO4 in strong basic medium and 1 mole of ferrous oxalate FeC204 is oxidised by y mole of MnO4 in acidic medium Ratio of x y is 02 1 0 10 1 03 1 01 3

of angular hodes and number of radial nodes in the orbital to which last electron of chromium present What is the total number of radial and angular nodes present in 5f orbital Infrared lamps are used in restaurants to keep the food warm The infrared radiation is strongly absorbed by water raising its temperature and that of the food If the wavelength of infrared radiation is assumed to be 1500 nm and the number of quanta of infrared radiation produced per second by an infrared lamp that consumes energy at the rate of 100 W and is 12 efficient only is xx 10 then the value of x is xis gy vsJ Given h 6 625 x 107 J s When an electron makes transition from n 1 state to n state the wavelength of emitted adiations is related to n n 1 according to x n What is the value of x

halpy of neutralisation of HCl by NaOH is 57 kJ mol and with NH4OH is 50 kJ mol late enthalpy of ionisation of NH4OH aq e energy of NaCl s is 790 kJ mol and enthalpy of hydration is 785 kJ mol ate enthalpy of solution of NaCl s mple of NH4NO3 is decomposed in a Bomb calorimeter The temperature of calorime se by 4 C The heat capacity of the system is 1 25 kJ C Calculate the value of x molar heat of decomposition of NH4NO3 at constant volume is 400 kJ mol engine operating between 227 C and 77 C absorbs 10 kcal of heat from the 227 bir reversibly per cycle Calculate total work done in kcal in two cycles ate work done in chemical reaction in kcal 3B g C l at 227 C at 1 atm in closed vessel ole ideal monoatomic gas is heated according to path AR and

The standard electrode potential E values of Al AI Ag Ag K K and Cr Cr are 1 66 V 0 80 V 2 93 V and 0 74 respectively the correct decreasing order of reducing power of the metal is NEET 2019 Odisha 1 Al K Ag Cr 2 Ag Cr AI K 3 K Al Cr Ag 4 K AI Ag Cr

In question if it ato is asked the product for the reaction HCCH Na K Then what to will be the answer Monosodium ethynide or Disodium ethynide CH CNa or Nae C Na La HERE How the Question can be given tricky in Neet to confuse the student Please help me clarify this cpt problem T

eal gas is expanded according to PV constant under very ligi tion mode active Calculate the molar heat capacity of gas in cal molK in is operating between 500 K to 300 K and it absorbs 10 kcal of heat from 500K sibly per cycle Calculate the work done in kcal per cycle le involving ideal non linear triatomic gas if during adiabatic expansion volume 2L to 16L and heat absorbed during isothermal expansion is 8 kcal then itude of work done by carnot engine in kcal olioxs 29mmob

me gram of a metallic chloride was found to contain 0 835 g of chlorine Its vapour density is 5 If its molecular formula is M CI then what is value of x y 875 g of crystalline barium hydroxide is dissolved in water For the neutralization of this ution 20 mL of N 4 HNO3 is required How many moles of water of crystallization are sent in one mole of this base Given Atomic mass Ba 137 0 16 N 14 H 1 M g of polybasic organic acid Molecular mass 600 required 100 mL of a NaOH solution 6 complete neutralisation Find the basicity of acid mixture contains 10 mole each of NaOH Na CO3 and NaHCO3 When half of mixture is ated with HCl it required x mole of HCl in presence

12 Ammong the following incorrect statement 1 NO has one unpaired electron in the antibonding molecular orbital 2 NO NO order of bond length 3 Magnetic moment of N is 3 BM 4 Magnetic moment of O is zero 9 2 112 3t 1 NO farfar se 4 T 2 NO NO 3 BM 4

22 Mr Santa has to decode a number ABCDEF where each alphabet is represented by a single digit Suppose an orbital whose radial wave function is represented as below and angular function is 1 2 r k r k ekz r 5k r 6k3 From the following information given about each alphabet then write down the value of A B C D E F where each alphabet corresponds to a value Info A Value of n where n is principal quantum number Info B Number of angular nodes Info C Azimuthal quantum number of subshell to which orbital belongs Info D Number of subshells having energy between n 5 s to n 5 p where n is principal quantum number Info E Orbital angular momentum of given orbital Info F Radial distance of the spherical node which is farthest from the nucleus Assuming k 1