Physical Chemistry Questions

The concentration of H and concentration of OH of a 0 1 aqueous solution of 2 ionised weak acid is Ionic product of water 1 10 4 CBSE PMT 1999 DPMT 2004 a 2x10 M and 5x10 M b 1x10 M and 3 10 M c 0 02x10 M and 5 10 11 M d 3x10 2 M and 4x10 13 M

0 The total number of different kind of acidic buffers obtained during the titration of H PO with NaOH are A 3 B 1 C 2 D 0

31 12 grams of a mixture of sand and calcium carbonate on strong heating produced 7 6 grams of residue How many grams of sand is present in the mixture SERIES for Sri Chaitanya 23

Element A has 3 electrons in the outermost orbit and element B has 7 electrons in the outermost orbit The formula of the compound formed between A and B would be 1 A B3 3 A B 2 A3B6 4 AB3

The solubility of a salt of weak acid AB at pH 3 is Y x 103 mol L The value of Y is Given that the value of solubility product of AB Ksp 2 x 10 10 and the value of ionization constant of HB K 1 10 2018

39 The yield of product in the reaction 2A g B g would be lower at A low temperature and low pressure C low temperature and to high pressure IIZI co pageno 1 2C g QkJ B high temperature high pr D high temperature low pre

A 10 cm air column is trapped inside the tube having uniform area of cross section by 6 cm of Hg and is placed horizontally to the plane Calculate the length of air column when the tube is placed vertically with opened end up 1 9 26 cm 2 10 cm 3 10 25 cm 4 11 5 cm

46 If pK for CN at 25 C is 4 7 The pH of 0 5M aqueous NaCN solution is 1 12 2 10 3 11 5 4 11

79 Observe the given boundary surface diagrams of two orbitals I and II and choose the correct option Z II I d22 II dyz b I d II d a I d c I I dz II d yz II d d I dxy II dxz

10 101 ei nijulpe to jaio emilion The cryoscopic constant for acetic acid is 3 6 K kg mol A solution of 1 g of a hydrocarbon in 100 g of acetic acid freezes at 16 14 C instead of the usual 16 60 C The hydrocarbon contains ositib 0 C01 di noitu 92 3 carbon What is the molecular formula 10120 0 70m

On adding a non volatile solute to a solvent the vapour pressure of solvent decreases and becomes z x vapour pressure of solvent where z is 1 mole fraction of solvent 2 mole fraction of solute 3 molality 4 molarity

The enthalpy change for a reaction does not depend upon a use of different reactants for the same products b the nature of intermediate reaction steps c the differences in the initial and final temperatures of involved substances d the physical sate of reactants and products

3 When weak acid is titrated with strong base then pH before after reaching end point respectively 1 pK pK pK salt acid 2 pK log PK 3 7 PK logc pk log salt 4 pK log cid a salt acid 1 7 pK logc

03 Addition of lyophilic solution to the emulsion forms a a protective film around the dispersed phase b a protective film around the dispersion medium c an aerosol d true solution 16 or

Specific conductivity of a solution a increases with dilution b decreases with dilution c remains unchanged with dilution d depends on mass of electrolyte cot

The temperature at which intermolecular attraction force balance the intermolecular repulsion force is known as 1 Boyle temperature in 2 Critical temperature 3 Boiling temperature 4 Equilibrium temperature

5 An organic compound on analysis gave C 54 2 H 9 2 by mass Its empirical formula is a CHO CH 0 c C H O C H O The relative number of atoms of elements X and Y in b d

D Volume of a tyre 10 litre when inflated The tyre is inflated to a pressure of 3 atm at 17 C with air Due to driving the temperature of tyre increases to 47 C a What would be the pressure at this temperature b How many litre of air measured at 47 C and pressure of 1 atm should be let out to restore the tyre of 3 atm at 47 C

7 Formation of ethane from calcium carbide takes place as follows CaC 2H O Ca OH C H C H 2H C H6 The amount of ethane gas obtained from 72 kg of water is 1 60 kg 3 40 kg 2 20 kg 4 52 kg

8 A completely filled d orbital d 0 is of a spherical symmetry b octahedral symmetry c tetrahedral symmetry d unsymmetry

1 10 mL of 1 mM surfactant solution forms a monolayer 2 covering 0 24 cm on a polar substrate If the polar head is approximated as a cube what is its edge length 2019 Main 9 April II d 2 0 nm a 2 0 pm b 0 1 nm c 1 0 pm

35 Ammonium chloride when dissolved in water leads to cooling sensation The dissolution of NH Cl at constant temperature is accompanied by 1 Increase in entropy 2 Decrease in entropy 3 No change in entropy 4 No change in enthalpy

In a face centered lattice with all the positions occupied by A atoms the body centered octahedral hole in it is occupied by an atom B of appropriate size For such a crystal calculate the void space per unit volume of unit cell Also predict the formula of the compound

7 Which d orbital has different shape from rest of al d orbitals 16 ertainty of b da d day or dys

7 Air can oxidize sodium sulphite in aq solution but cannot do so in the case of sodium arsenite If ids however air is passed through a solution containing both sodium sulphite sodium arsenite then bot are oxidized This is an example of 1 Positive catalysis 2 Negative catalysis 4 Auto catalysis 3 Induced catalysis

AH 298 2 kJ SO3 AH 98 7 kJ H SO4 AH 130 2 kJ H O AH 287 3 kJ If S O SO SO2 2 02 SO3 H O H 2 0 Then the enthalpy of formation of H2SO4 at 298 K will be a 814 4 k c 650 3 kJ b 320 5 kJ d 933 7 kJ

A B C and D are four metals A can displace D from its salt solution but B and C cannot displace D B can displace hydrogen H for a dilute solution of a mineral acid but C cannot The reduction potentials of A B C D and H i e hydrogen are in the order A C H B D A B A B C D H D H A C D B C A D B H C

In the intramolecular Cannizzaro s reaction when glyoxal is reacted with concentrated NaOH the n factor of glyoxal is 1 4 3 2 2 3 4 1

separate 1 Chloroform and Aniline 2 Ether and Toluene 3 Hexane and Toluene

When SO is passed through the solution of potassium iodate the oxidation state of lodine changes from 1 5 to 0 3 5 to 0 2 5 to 1 7 to 1

144 At temperature T a compound AB g dissociates according to the reaction 2AB g 2AB g B g with a degree of dissociation x which is small compared to unity Deduce th expression for x in terms of the equilibrium constant Kp and the total pressure

Hydrolysis of sucrose is given by the following reaction Sucrose H 0Glucose Fructose If the equilibrium constant K is 2 10 at 300 K the value of AG at the same temperature will be 2 3 4 8 314 J mol K 1x300 Kx ln 2 1013 8 314 J mol K 300 K ln 2 101 8 314 J mol K 300 K In 3 101 8 314 J mol K 300 K ln 4 1013

a IIT 2001 4 A graph is plotted between PV along Y axis and P along X axis where Vm is the molar volume of a real gas Find the intercept along Y axis IIT 2004

5 A mixture of SO and O in the molar ratio 16 1 is diffused through a pin hole for successive effusions three times to give a molar ratio 1 1 of diffused mixture Which one are not correct if diffusion is made at same P and T in each operation I Eight operation are needed to get 1 1 molar ratio II Rate of diffusion for SO O after eight operations in and 0 707 III Six operations are needed to get 2 1 molar ratio for SO and O in diffusion mixture IV Rate of diffusion for SO and O after six operations is 2 41 1 I II III 3 I III 2 II III 4 IV

One or more than one correct option 11 The following is are endothermic reaction s a Combustion of methane b Decomposition of water c Dehydrogenation of ethane to ethylene d Conversion of graphite to diamond

578 The principle chromatography is 1 Adsorption 3 Solubility involved min in paper 2 Partition 4 Volatility

How many moles of KMnO are reduced by 1 mole of ferrous oxalate in acidic medium 76 How 1 1 2 5 3 HOS 1 3 3 4 3 GH

28 How much water is added to 100 ml 0 5M H SO4 solution so that its molarity becomes 0 1M 1 500 ml 2 400 ml 3 100 ml 4 200 ml

28 O In an ionic solid 1 6 A and Use the radius ratio rule to determine the edge length of the cubic unit 0 cell is A A 4 B 2 3 C 3 3 D 4 3

Lyophilic colloidal solution can be coagulated by 1 addition of high concentration of electrolyte 2 By addition of solvent like C H OH 3 By addition of excess H O 4 Both 1 2 correct

The IUPAC name of sec butyl chlor

56 The modern atomic weight scale is based on a C 2 b 016 c H d C 3

1 The density of helium is 0 1784 kg m at STP If a given mass of helium at STP is allowed to expand to 1 400 times of its initial volume by changing P and T compute its resultant density

28 What is the molarity and molality of a 13 solution by weight of sulphuric acid with a density of 1 02 g mL To what volume should 100 mL of this solution be diluted in order to prepare a 1 5 N solution le 1978 2M HO a 0 027 mmHg b 0 031 mmHg c 0 017 mmHg d nac 0001 bulib 3M

A 0 0020 m aqueous solution of an ionic compound Co NH3 5 NO CI freezes at 0 00732 C Number of moles of ions which 1mol of ionic compound produces on being dissolved in water will be K 1 86 C m 1 1 2 2 3 3 4 4

84 A drop 0 05 mL of 12 M HCI is spread over a thin sheet of aluminium foil thickness 1x10 cm and density 2 7 gmL Assuming whole of the HCI is used to dissolve Al The maximum area of hole produced in the foil is 1 2x10 cm 2 2 20 10 cm 3 200 10 cm 4 2000 10 cm

1 00g of a non electrolyte solute molar mass 250g mol was dissolved in 51 2g of benzene If the freezing point depression constant K of benzene is 5 12 K kg mol 1 the freezing point of benzene will be lowered by 2 0 3 K 4 0 2 K 1 0 4 K 3 0 5 K

ed K for benzene 5 12 kg mol K The molar volume of liquid benzene density 0 877 g ml increases by a factor of 2750 as it vaporizes at 20 C and that of liquid toluene density 0 867gml increases by a factor of 7720 at 20 C A Solution of benzene toluene has a vapour pressure of 46 0 torr Find the mole fraction of benzene in the vapour above the solution orallol glectrodes of cross section area 4cm

2 55 N 10 acetic acid was titrated with B 0 05 56 When 20 ml of M 20 N 10 the pH of the solution will be K 10 A 5 log 1 3 5 5 log 3 C 5 log 1 3 5 5 log 3 C 0 05 NaOH When 25 50 and 75 of titration is over then 0 100 B 5 log 3 4 5 log 1 3 D 5 log 1 3 4 5 log 1 3 NaOH are added to 10 ml of D 2 5 M HC

A rigid container contain 1 Kg m N gas at 400 K if final temprature is 800 K then find change in entropy kJ K Given C 29 099 joule to doidW P OHO HD di 1 512 86 joule pitan 2 1025 736 joule 3 256 43 joule 4 170 9 joule