Physical Chemistry Questions

6 02 x 1020 molecules of a substance weigh 44 mg What is the molar mass of the substance

19 Although q is a path dependent function but q is independent P of path because a AH is independent of path b U P and V are state functons and H depends on them c both a and b A d none of these 9000 b

2 molecules ions 1 XeF4 4 SiF4 2 BF AIEEE 2006 The decreasing values of bond angles from NH3 1069 to SbH3 919 down group 15 of the periodic table is due are all the bonds not equal 3 SF4 to 1 decreasing lp bp repulsion 3 increasing bp bp repulsion 2 increasing electronegativity 4 increasing p orbital character in sp In which of the following ionization process the bond order has increased and the magnetic behaviour has changed AIEEE 2007

If 100 mL of 0 100 M Na SO is added to 200 mL of 0 150 M NaCl what is the concentration of Na ions in the final solution Assume that the volume are additive A 0 133 M B 0 167 M C 0 250 M D 0 350 M illilitan of 0 300 M phosphoris

Calculate the mass of non volatile solute having molecular mass 40 which should be dissolved in 57 gm octane to reduce its vapour pressure to 80

No of oxalic acid molecules in 100 mL of 0 02 N oxalic acid are a 6 023 1020 c 6 023x1022 b 6 023x1021 d 6 023 x 1023

If uncertainty of position of electron is zero the uncertainty in its momentum would be a Zero b h 2n c h 4 d x 8

9 The vapour pressure of an aqueous solution of glucose is 750 mm Hg at 373 K The molality of this solution at the same temperature is 1 0 74 molal 2 0 84 molal 3 0 70 molal 4 0 50 molal

46 A metal X crystallises in a face centred cubi arrangement with the edge length 862 pm What is the shortest separation of any two nuclei of the atom b 707 pm d 609 6 pm a 406 pm c 862 pm

The vapour pressure of two pure liquids A and B that form an ideal solution are 100 and 900 torr respectively at temperature T This liquid solution of A and B is composed of 1 mole of A and 1 mole of B What will be the pressure when 1 mole of mixture has been vaporized a 800 torr b 500 torr c 300 torr d None of these rectly the changes in thermodynamic properties during

When a vander waal s gas undergoes free expansion then it MP PET 2009 temperature a Decreases b Increases c Does not change d Depends upon the nature of the gas

A beam of specific kind of particles of velocity 2 1 x 107 m s is scattered by a gold nuclei Find out specific charge charge mass of this particle if the distance of approach is 2 5 10 4 m a 4 84 107 C kg b 4 84 x 10 7 C kg c 2 42 x 107 C kg d 3x10 12 C

1 Consider the change in oxidation state of bromine corresponding to different emf values as shown in the given diagram dillups HBrO 3000 BrO 1 82 V BrO 3 4 ad obru ohas oe VEW BUL ai fiduridiliups 1 0652 V Br BrO3 1 5 V HBrO Br2 1 595 V go to tolls disproportionation Then the species undergoing is a BrO3 c Br2 UT 1 noi HBrO b BrO4 e 00 21 bon dieroverdi b BrO4

The composition What percentage III of a sample of wustite is Fe 0 9301 of iron is present in the form of IIT 199

Number of atoms in 558 5 g Fe at wt 55 85 is AIEEE 2002 a Twice that in 60 g carbon b 6 023x1022 c Half in 8 g He 5022x 1023

4 Select the incorrect 1 Extensive properties are additive in nature 2 Intensive properties are mass independent 3 Vapour pressure is an extensive property 4 Pressure is an intensive property

4 5 4 Q 3 50 mL of 0 2 M ammonia solution is treated with 25 mL of 0 2 M HCl If pK of ammonia solution 4 75 the pH of the mixture will be JEE MAIN Online 2017 1 8 25 2 4 75 3 9 25 4 3 75

4 The nodal plane in the bond of ethene is located in A the molecular plane B a plane parallel to the molecular plane C a plane perpendicular to the molecular plane which bisects the carbon carbon a bond a D a plane perpendicular to the molecular plane which contains the carbon carbon bon

The density of 3M solution of sodium thiosulphate Na S O is 1 58 g ml Calculate amount of Na S O in w w i mole fraction of Na S O iii molality of Na and S O2 ions Calculat

Density of Li atom is 0 53 g cm 3 The edge length of Li is 3 5 Find out the number of Li atoms in an unit cell NA 6 023 x 1023 M 6 94 g mol 1 0153x6023x10 X 1 2 4 66 9 2 8 3 4

When Zn Cu 1 the electrical potential of Daniell cell is 1 1 V However a When E 1 1 V current flows from Zn to Cu ext b When Ext 1 1 V current flows from Cu to Zn c When E 1 1 V current flows from Zn to Cu ext d When F 1 V Walantrong flow from

A certain radio isotope zXA t1 2 10 days decays to given z 2YA 4 If one g atom of zXA is kept in a sealed vessel how much He will accumulate in 20 day at STP Roorkee 1987

51 Which of the following is not primary standard a Na CO3 10H 0 b Oxalic acid 10H 0 d NaOH 52 c Na B407 The mole

The number of moles of KMnO reduced by one 4 mole of KI in alkaline medium is SVILD 1 One 2 Two 3 Five 4 One fifth

100 ml of 3 mol H SO reacts with 100 ml of 3 mol NaOH Enthalpy of neutralisation of reaction will be 1 57 1 kJ mol 3 0 3 x 57 1 kJ 2 2 x 57 1 kJ 4 3 57 1 kJ

Which has minimum number of atoms of oxygen Kame X10 ml H 0 e 2 0 1 mol of V 05 s Begr 3 12 gm O g 4 12 04 x 1022 molecules of CO I male 1

Which of the following sets of quantum numbers represents 2007 the highest energy of an atom a n 3 1 0 m 0 s 1 2 b n 3 1 1 m 1 s 1 2 c n 3 1 2 m 1 s 1 2 d n 4 1 0 m 0 s 1 2

16 In aqueous solution the ionization constants for carbonic acid are K 4 2 107 and K 4 8 10 1 Select the correct statement for a saturated 0 034 M solution of the carbonic acid 2 1 The concentration of H is double that of CO 2 The concentration of CO2 is 0 034 M 2 3 The concentration of CO3 is greater than that of HCO3 4 The concentrations of H and HCO3 are approximately equal AIEEE 2010 I will Motions start precipitating

From the following bond energies H H bond energy 431 37 kJ mol C C bond energy 606 10 kJ mol C C bond energy 336 49 kJ mol C H bond energy 410 50 kJ mol Enthalpy for the reaction H H H H C C H HH C C H H H will be 1 553 0 kJ mol 1 OH H 2 1523 6 kJ mo

For an ideal gas consider only P V work in going from an initial state X to the final state Z The fina state Z can be reached by either of the two paths shown in the figure Which of the following choice s is are correct Take AS as change in entropy and w as work done P atmosphere X Z V litre a ASx z ASX y ASy Z b wx z Wx y Wy Z c WX Y Z Wx Y

72 In a reaction 4 mole of electrons are transferred to one mole of HNO when it acts as an oxidant The possible reduction product is 1 1 2 mole N 2 1 2 mole N O 4 1 mole NH 3 1 mole of NO

526 3 mL of 0 5 m HCl is shaken with 0 5 g of activated charcoal and filtered The concentration of the filtrate is reduced to 0 4 m The amount of adsorption x m is

C In a reversible reaction K K and AH 40 KCal The product will be obtained in less amount at 1 High pressure high temperature 2 Low pressure low temperature 3 High pressure low temperature 4 Low pressure high temperature

must 3 Equimolal solutions of KCl and compound X in water shows depressions in freezing point in the ratio of 4 1 Assuming KCl to be completely ionized the compound X in solution 02 11 to w loM 02 H to virstom od statusle a dissociate to the extent of 50 b hydrolyse to the extent of 80 c dimerize to the extent of 50 d trimerize to the extent of 75 llo sd to do MIRI 101

5 Chloride samples are prepared for analysis by using NaCl KCl and NH4Cl separately or as mixture What minimum volume of 5 by weight AgNO3 solution sp gr 1 04g mL must be added to a sample of 0 3g in order to ensure complete precipitation of chloride in every possible case

22 Coagulating power of NaCl and AlCl is 51 and 0 093 respectively AlCl coagulates x times faster than NaCl The value of x is a 530 b 565 1 of c 548 isted d 570 E minde har Id

c 90 a 0470 0 10 g of a sample containing CuCO and some inert impurity was dissolved in dilute sulphuric acid and volume made up to 50 mL This solution was added into 50 mL of 0 04 M KI solution where copper precipitates as Cul and I is oxidized into I3 A 10 mL portion of this solution is taken for analysis filtered and made up free I3 and then treated with excess of acidic permanganate solution Liberated iodine required 20 mL of 2 5 mM sodium thiosulphate solution to reach the end point Determine mass percentage of CuCO3 in the original sample a 7 41 c 61 75 b 74 1 d None of these

38 What volume of 0 20 M H SO4 is required to produce 34 0g of H S by the reaction 8KI 5H SO4 4K2SO4 412 H S 4H O

The ratio of number of moles of KMnO4 and K Cr O required to oxidise 0 1 mol Sn to Sn 4 in acidic medium 1 6 5 3 1 2 2 5 6 4 2 1

1 HNO acts as an oxidant with which one of the following reagent 1 KMnO 2 H S 3 K Cr O 4 Br

5 ASF molecule is trigonal bipyramidal The orbitals of As atom involved in hybridisation are a d d S PxPy b dxy S Px Pp Pz c S Px Py Pz dz d2 2 S Px Py Pr d

The percentage of sodium in a breakfast cereal labelled as 110 mg of sodium per 100 g of cereal is a 11 b 01 10 d 110 c 0 110

3 36 The coagulation values of AICI and NaCl are 0 093 and 52 respectively Then coagulating power of AICI as compared to that of NaCl is a 52 x 0 093 times b 52 0 093 times c 0 093 52 times d None of these

112 The reaction N O4 g 2NO2 g is started with 0 8 moles of N O4 in a one litre vessel What is the equilibrium concentration of NO if equilibrium constant is 0 00466 at 298 K a 0 06 M c 0 74 M b 0 03 M d 0 36 M

2 40 At what pH does an indicator change colour if the indicator is a weak acid with K 4x 10 F which one s of the following neutralizations would the indicator be useful Explain ind a NaOH CH COOH b HCI NH c HCl NaOH What indicator should be used for the titration of 10MKH BO with 1MUCH 0 41

d None of these A sol is prepared by addition of excess of AgNO3 solution in KI solution The charge likely to develop on colloidal particles is ugh b negative d both charges numbers of protective colloids A B C and D are 0 04 0 004 10 and 40 respectively a positive c no charge

6 The potential energy of the electron present in the ground state of Li2tion is represented by 38 a b TEO c 4TE OT d 3e 4TE OF 3e 4TE OF

n factor of HCI in the reaction KMnO HCI KCI MnCl Cl H O 4 1 1 2 6 3 5 8 4 00 L

A cylinder fitted with a piston contains 0 10 moles of air at room temperature 20 C The piston is pushed so slowly that the air within the cylinder remain essentially in thermal equilibrium with the surroundings The work done by the air within the O cylinder if the final volume is one half the initial volume

Polychlorinated biphenyls PCBs known to be dangerous environmental pollutants are a group of compounds with the general empirical formula C HC10 m where m is an integer What is the value of m and hence the empirical formula of the PCB that contains 58 9 chlorine by mass