Physical Chemistry Questions

Purification of chromium can be achieved by electrorefining chromium from an impure chromium anode onto a pure chromium cathode in an electrolytic cell How many hours will it take to plate 13 0 kg of chromium onto the cathode if the current passed through the cell is held constant at 41 0 A Assume the chromium in the electrolytic solution is present as Cr

Consider the bcc unit cells of the solids 1 and 2 with the position of atoms as shown below The radius of atom B is twice that of atom A The unit cell edge length is 50 more in solid 2 than in 1 What is the approximate packing efficiency in solid 2 A A JEES A 1 45 53 TEN A 11 CO 2 65 B Solid 2 AY 000 A JEE Main 2019 A

An elevation of 0 70K was observed in a solution containing 12 5 g of non electrolyte substance in 175 g of water Calculate the molar mass of the substance Molal elevation constant Kb for water is 0 52 K kg mol 1 53 2 65 3 84 4 79 85 12 5 9412 Kb 1 5 2 E 3 4 7

A ABCABC B ABACABAC An ionic compound AB has ZnS type structure If the radius A is 22 5 pm then the ideal radius of B would be D none of these A 54 35 pm B 100 pm C 145 16 pm In diamond carbon atom occupy FCC lattice points as well as alternate tetrahedral voids If edge length

2s subshell is greater in size than 1s subshell Similarly 2p 3p 4p subshells have similar shapes but their sizes increase in the order 2 p 3p 4p Orbital angular momentum of an electron is calculated using the expression 1 1 I I 1 h 2 h 2 here The magnitude of magnetic momentu may be given as L 1 1 1 BM where BM Bohr Magneton eh 4 m 1 BM 9 2732 10 4 J Maximum electrons present in a subshell 2 21 1 s subshell 2 electrons p subshell 6 electrons g subshell 18 electrons d subshell 10 electrons f subshell 14 electrons 3 Magnetic Quantum Number

The reduction potential of H electrode in a solution of 0 1 M H aq is PH 1 atm 0 0591 V 0 591 V nr min 0 0591 V

If the resulting potassium carbonate weighs 0 745 g and the calculated yield is 0 690 g what is the percent yield General Exercises percent V AXO SZA

6 Match the following Column I A Vitamin B12 B Wilkinson catalyst C Blood pigment D Ziegler Natta catalyst 1 A c B e C b D d 2 A d B b C e D a 3 A c B e C b D a 4 A b B c C e D a Column II a Ti b Fe c Co d Mg e Rh K

3 32 g of methane gas initially at 101 325 kPa and 300 K is heated to 550 K Given Cp m JK mol 12 552 8 368 x 102T K Assuming that methane behaves ideally calculate w q AE and AH for an isobaric reversible process 5

One mole of N gas at 0 8 atm takes 38 seconds to diffuse through a pin hole where as one mole of an unknown compound of xenon with fluorine at twice the pressure of N takes 55 seconds to diffuse through the same pin hole How many lone pairs are around xenon in xenon fluoride compound Given atomic masses Xe 121 u F 19 u

8 Element B forms ccp structure and A occupies half of the octahedral voids while oxygen atoms occupy all the tetrahedral voids The structure of bimetallic oxide is JEE Main 2019 1 A B 0 3 A B 0 2 AB 0 4 A BO4

7 The radius of the largest sphere which fits properly at the centre of the edge of a body centred cubic unit cell is Edge length is represented by a JEE Main 2019 1 0 027 a 3 0 067 a 2 0 047 a 4 0 134 a

on a clear day at sea level with a temperature of 25 degrees Celsius the partial pressure of N2 in air is 0 78 atm and the concentration of nitrogen in water is 5 3 x 10 4 M When the concentration in water is 1 1 x 10 3 M what is the partial pressure of N2

1 Identify the semiconductor have very fast response and have revolutionized the design of semiconductor devices 1 Si doped with group 13 element 2 Ge doped with group 15 element 3 GaAs 4 VO WL 1 Cal 6 11 10 1 ohm c 3 ohm cm 19 A for AB m 91 0 S cm cm mol 1 180 3 3 420 2 20 Given

Which of the following aqueous solutions shows maximum electrical conductivity 0 2 M HCN 0 2 M CH3COOH 0 2 M H CO3 hr min 0 2 M H SO4

Example 24 The solubility product of Ag C 0 at 25 C 0 1520 mole in 500 mL of water is shaken with excess of 1 29 x 10 mol L A solution of K C O4 containing Ag CO till the following equilibrium is reached Ag CO3 K C O Ag C O K CO At equilibrium the solution contains 0 0358 mole of K CO Assuming the degree of dissociation of K C O4 and K CO3 to be equal calculate the solubility product of Ag CO i e JIT

An ideal gas is allowed to expand both reversib irreversibly in an isolated system If T is the initial temperature and Tis the final temperature which of the following statements is correct a Trev Timev b TT for both reversible and irreversible processes c Tirrev Trev d TT for reversible process but T T for irreversible process

A certain sample of cuprous sulphide is found to have the composition Cu S because of incorporatio 1 92 of Cu ions in the lattice What is mole percent of Cut in total copper content in the cyrstal A 95 8 B 92 C 8 D 4 17

When alpha particles are sent through a thin metal foil most of them go straight through the foil because A alpha particles are much heavier than electrons C most part of the atom is empty space B alpha particles are positively charged D alpha particles move with high speed For a wave frequency is 10 Hz and wavelength is 2 5 m How much distance it will travel in 10

2 An aqueous solution of a certain organic compound has a density of 1 063 gmL an osmotic pressure of 12 16 atm at 25 C and a freezing point of 1 03 C What is the molar mass of the compound 334 g mol

13 At 100 C copper Cu has FCC unit cell structu with cell edge length of x A What is th approximate density of Cu in g cm at th temperature Atomic Mass of Cu 63 55 u JEE Main 201 1 3 422 X 105 X 4 205 211 X

An element with molar mass 2 7 x 10 2 kg mol forms a cubic unit cell with edge length 405 pm If its density is 2 7 x 10 kg m the radius of the element is approximately x 10 12 m to th nearest integer JEE Main 2020

C most part of the atom is empty space D alpha particles move with high speed For a wave frequency is 10 Hz and wavelength is 2 5 m How much distance it will travel in 40 secon

Calculate the reduction potential of a half cell having reaction Ag S s 2e 2Ag S S aq in a solution buffered at p 3 and which is also saturated with 0 1M H S aq Given K Ag S 10 Kal Ka 10 E As Ag 2 303 RT F 0 06 A 0 19V B 0 19 C 1 18V D 1 18 V 0 8V

2 The ratio of number of atoms present in a simple cubic body centered cubic and face centered cubic structure are respectively JEE Main 2019 1 4 2 3 3 8 1 6 2 4 2 1 4 1 2 4 Tower Pusa Road New Delhi 110005 Ph 011 47623456

Amount of electricity required to reduce 0 5 mole of A1 ions to Al atoms is 3 F 2 F hr 0 5 F

Of the following species which has the highest bond order and shortest bond length NQ NO NO2 NO 1 NO only 2 Bond order of NO is highest and bond length of NO2 is shortest 3 NO only 4 NO2 only 2 12

Example 1 3 An element has a body centred cubic bcc structure with a cell edge o 288 pm The density of the element is 7 2 g cm How many atoms ar present in 208 g of the element Solution Volume 11 1099

A 10 sec He B 20 sec 0 C 25 sec CO D 55 sec CO The ionization energy of the ground state hydrogen atom is 2 18x10 18 J The energy of an electro second orbit of He will be A 1 09x10 8 J B 4 36x10 J C 2 18x10 8 J D 2 18x10 8 J

D 57 180 Aqueous solution of which has highest boiling point 0 02 M K SO4 0 01 M glucose 0 01 M AICI 3 0 01 M NaCl Solution Answer 1 When number of solute particles increase in the solution the boiling point of solution increases

2 56 A solution of a non volatile solute in water freezes at 0 30 C The vapour pressure of pure water at 298 K is 23 51 mm Hg and K for water is 1 86 degree mol The vapour pressure of rain solution at 298 K is mm Hg

When FeO is heated in presence of oxygen it gets converted into Fe2O3 A mixture of FeO and Fe2O3 when heated in air it gain 3 in weight If the simplest mass ratio of FeO to that of Fe2O3 is x y then the value of y x is 10

When electrochemical cell is changed into electrolytic cell then why sign of cathode positive only Has ncert mentioned it wrobg in the diagram pls tell corre ct explanation teacher properly c Cathode ve Zn ZnSO4 Eext 1 1 W e CuSO4 Current Anode ve Cu ii No cha reacti When Eext 1 i Electrons e from Cuper and curre from Zn t ii Zinc is de at the zind electrode a copper diss copper elec

A metal crystallises in a face centred cubic structure If the edge length of its unit cell is a the closest approach between two atoms in metallic crystal will be JEE Main 2017 1 2a 3 2a a 2 2 4 2 2a

A compound of formula A B has the hcp lattice Which atom forms the hcp lattice and what fractic of tetrahedral voids is occupied by the othe atoms JEE Main 2015 1 hcp lattice B Tetrahedral voids A 3 2 hcp lattice A WIN N Medi Tetrahedral voids B

Vapour pressure of binary solution of two miscible 1 and volatile liquids when half of the liquid solution goes into vapour phase 2 Vapour pressure of two binary miscible and 2 volatile liquids R Vapour pressure of binary solution of two 3 immiscible and volatile liquids 5 Vapour pressure of binary solution having non 4 volatile solute P P P Po Po pop Po Pg XA Pg A B B V List II A B XB

Compound A decomposes according to the equation A g 2 B g C g A sealed 1 00 L container initially contains 1 84 10 3 mol of A g 1 28 10 3 mol of B g a 5 51 104 mol of C g at 100 C At equilibrium A is 2 10 10 3 M Find B and C Solve for the equilibrium concentrations of B and C Bleq x 10 M

Consider a 100 gm oleum sample which is labelled as 110 H SO4 After adding only sufficient amount of water that can react only with free SO3 If x grams of pure H SO4 can be obtained from the solution Then the value of x 100 is 2

How much amount of water can be decomposed through electrolysis by passing 2 F charge 2 5 mol of water 3 mol of water 3 5 mol of water 1 mol of water

How many of the following statements are correct 1 In CCP distance between two nearest octahedral voids is 2R 2 In CCP distance between nearest tethrahedral and octahedral voids is 2 3R 3 In CCP distance between two nearest voids is 2R 522 4 In CCP distance between next nearest tetrahedral void and farthest octahedral voids is 5R 5 In HCP along every edge centres of two tetrahedral voids and one octahedral void is located 3h 6 In HCP if a plane is passed parallel to top face but at from bottom it pass through centres of octahedral voids h is the height of ionsmatic unit cell 4 7 In HCP top plane pass through centres of both tetrahedral and octahedral voids orrect Answer 2 00 our Answer 4 our Status Incorrect

One of the resonating structure of SO is 4 452 0 Which set of formal charge on oxygen and bond order is correct 1 0 5 and 1 5 2 1 5 and 3 3 2 and 3 4 4 16x6 5 4 1 5 and 1 5

How long would it take a radio wave of frequency 6 10 sec to travel from mars to the earth a distance of 8 x 107 km Rutherfords experiment which established the nuclear model of atom used a heam of

Consider the change in oxidation state of bromine to different emf values as shown in the corresponding given diagram BrO 1 82 V Bro BrO3 1 0652 V Br 1 5 V HBrO 1 595 V Br Then the species undergoing disproportionation is a BrO b Bro c Br d HBrO

4 a What is the molarity of a solution prepared by dissolving 10 00 g of NH4 3PO4 in water to make 1 25 L of solution PDy TAY 10 00 NPD 10 0 671 m 149 NH I 0 71 mol Nhu Du NH 1 200 M 140g mol Volume 1 254 Mass 10 00g NH ePO4 0 58688M b What is the molarity of the ammonium ions in the solution described in part a

What is the advantage of squaring the wave function and then plotting against distance from the nucleus 1 Function becomes continuous 2 All the values becomes positive 3 Wave function stops showing two solutions at a point 4 The value 4 at r 0 becomes zero

9 According to the lesson who was the audience when Bismillah Khan poured his heart out into Raag Kafi from the Red Fort 0 5 Points a Pandit Jawaharlal Nehru b Mahatma Gandhi c Rajendra Prasad

10 Which of the oxides behaves as metallic or properties depending on insulating temperature 1 SiO 3 TiO 2 TiO3 4 ReO3 17 Which conducta 1 5M K 3 0 05M 18 Unit for

Which type of defect has the presence of cations in the interstitial sites JEE Main 2018 1 Schottky defect 2 Vacancy defect 3 Frenkel defect 4 Metal deficiency defect

Consider Henry s Law constant for some gases in water Gas Temperature KKH Kbar Ar 298 CO 298 IHCHO 298 CH4 298 40 3 1 67 1 83 x 10 5 0 413 Arrange these gases in increasing order of solubility in water CO Ar HCHO CH4 Ar CO HCHO CH4 CO Ar CH4 HCHO Ar CO CH4 HCHO

N A cubic solid is made by atoms A forming close pack arrangement B occupying one Fourth of tetrahedral void and C occupying half of the octahedral voids What is the formula of compound 8V inc al that contain Titanium and oxygen if structur util