Physical Chemistry Questions

4 Gamma potential 19 The maximum power to precipitate arsenious sulphide is of 1 H SO 4 2 Na3 PO4 man h 3 CaCl 4X AICI LAX

Q 50 An aqueous solution of KIO3 was treated with excess of KI solution The solution is acidified HCl The liberated I2 consumed 10ml of 1 0M thiosulphate solution to decolourise starch iodine cor Then millimoles of KIO3 consumed are

What weight of CO is required to form Re CO 10 from 3 g of Re2O7 according to given reaction Re O7 CO Re CO 10 CO Atomic weight of Re 186 2 C 12 and O 16 convert in nearest integer

The rate constants k and k for two different reactions are 1016 e 2000 T and 1015 e 1000 T respectively The temperature at which k k is 2000 1 K 2 303 2 2000 K 1000 K 2 303 3 4 1000 K

cylindrical base 7 A container 821 cm fitted with frictionless massless piston consist of five valves such as I II III IV and V The distance of valves from the initial position of piston is 15 30 40 45 and 50 cm respectively The initial height of piston from the base of container was 60 cm These valves open automatically if pressure exceeds over 1 5 2 2 2 5 4 4 and 4 8 atm respectively Under the given conditions shown in the diagram the system is in state of equilibrium The piston is now compressed moved downward slowly and isothermally Neglect the volumes of valve connectors Valve I Valve III T Valve V P 1 atm T 300 K Valve II Valve IV in the container are area a Value II will be opened first b As the piston crosses the value which will be opened first the remaining number of moles 5 3 c Value V will be the second value which open d Number of moles will be zero as the piston

1 c c N O at NTP contains 1 8 224 1 2 3 x102 2 atoms 6 02 22400 1 32 224 x1023 molecules 23 10 3 electrons AS ATT of above

2 The temperature at which a first order reaction with activation energy 191 5 kJ and Arrhenius factor of 10 2 s will have a half life period of 693 seconds is a 666 7 K b 1000 K d 333 3 K c 1555 5 K

1 mol of a non ideal gas undergoes the given change 2 atm 3 L 95 K 4 atm 5 L 245 K In this process if increase in internal energy of the gas is 30 L atm then what will be its change in enthalpy s The change in enthalpy AH A U PV AU A PV AU P V2 P1V Given AU 30 L atm P 2 atm P 4 atm 3L and V 5 L AH 30 4x5 2 x 3 L atm 441 atm

5 If the four tyres of car are filled to the same pressure with N O H and Ne separately then which one will be filled first 1 N 3 H 2 0 4 Ne

following terms ns i Cryoscopic Constant ii Parts per million b 100 mg of a protein is dissolved in enough water to make 10 0 mL of a solution If this solution has an osmotic pressure of 13 3 mm Hg at 25 C wh is the molar mass of protein R 0 0821 L atm mol K and 760 mm Hg 1 atm

A solution containing 2 68 x 10 3 mol of An ions requires 1 61 10 3 mol of MnO2 for the complete oxidation of Ant to AO in acidic medium What is the value of n

Al OH sol 2 3 CdS sol 4 Gum 0 25 g lyophilic colloid is added to 100 ml gold solution to prevent the coagulation on adding 1 ml 10 NaC solution What will be gold number of lyophilic colloid 1 250 0525 3 25 2 125 4 0 25 d number of Gelatin Gum and Starch are 0 005 0 15 and 25 respectively Which colloid has highe 25 0035 0 25

A certain ion Xn is oxidized successively to XO2 and then XO by a powerful oxidizing agent If the number of moles of the oxidizing agent required in the successive steps of oxidation are in the ratio 4 1 n is 1 3 3 2 2 1 4 4

95 Molar enthalpy of combustion for C H g C graphite and H g are 1300 394 and 286 KJ mole respectively then calculate of C C bond in KJ mole AHSub C graphite C graphite 715 KJ mole AHRE H H 436 KJ mole BE AHRE C H 413 KJ mole BE 1 415 3 1215dal 2 610 4 814

F P of solution 10 33 C Ans 10 33 C A 0 01 molal solution of ammonia freezes at 0 02 C Calculate the van t Hoff factor i and the percentage dissociation of ammonia in water KF H O 1 86 deg molal

If 20 ml of 0 5 M Na SO is mixed with 50 ml of 0 2 M H SO4 30 ml of 0 4 M Al SO4 3 solution Calculate Na H SO 2 A1 Assuming 100 dissociation moles

gas X is present with saturated water vapour over water liquid at total pressure of 1 5 atm Vapou essure of H O at same temperature is 0 5 atm What is the solubility of gas X in terms of mole 10 moles H O Partial pressure of X slope 38x10 torr mol frac of x in H O

Which of the following formulae expresses the law of equivalent correctly m E E a m b E E m m

p 0 5 x 0 082 x 300 14 76 atm Ans TC If 200 ml of 0 2 M BaCl solutions is mixed with 500 ml of 0 1 M Na SO4 solutions Calculate of resul solutions

Given the following reactions involving W X Y and Z are i X Z ii iii W Z W Z iv W Y No reaction On arranging W X Y Z in order of their increasing ability as reducing agent the correct option obtained is X Z X Z Y X No 1 X Z Y W 2 Z W Y X 3 Z X Y W reaction

So density 6 9 56 100 1 X 30 1 1288 g It Ans 10 ml of sulphuric acid solution sp gr 1 84 contains 98 by weight of pure acid Calculate the volume of 2 5 M NaOH solution required to just neutralize the acid 98

H O B OH 4 H K 5 9 10 10 Calculate pH of 0 3 M boric acid log 1 77 0 13 MIXTURE OF TWO OR MORE ACIDS BASES Q 12 Calculate pH of following solutions 0 1 M H SO4 50 ml 0 4 M HCl 50 ml log 0 3 0 522 b 0 1 MHA 0 1 MHB K HA 2x 10 5 K HB 4 x 105 log 6 0 39 Q 13 Calculate H and CHCI COO in a solution that is 0 01 M in HCl and 0 01 M in CHCI COOH Take K 3 x 10 2 30 5 5 Q 14 Calculate H CH COO and C H O in a solution that is 0 02 M in acetic acid and 0 01M in benzoic acid K acetic 1 8 x 10 5 K benzoic 6 4 10 5 POLYPROTIC ACIDS BASES Q 15 What are the concentration of H H C O4 HC 0 and C 02 in a 0 1 M solution of oxalic acid K 10 2 M and K 10 5 M Q 16 Calculate H H PO HPO and PO in a 0 01M solution of H PO4 Take K 10 K 108 K 10 13 HYDROLYSIS the OH concentration of a 0 08 M solution of CH COONa K CH COOH 1 8 10 5 10 51

25 The volume in mL of 0 1 M AgNO3 required to completely precipitate the chloride ions present in 30 mL of 0 01 M of Cr H O 5CI Cl as silver chloride is close to

If the weight of metal chloride is x gram containing y gram of metal the equivalent weight of metal will be 1 E x35 5 y 3 E Yx35 5 x y 2 E 4 E 8 y x X 8 x y y

0 2 g of a sample of H O2 required 10 ml of IN KMnO4 in a titration in the presence of H SO4 Purity of H O2 is A 25 C 85 B 65 D None of these of KMnO that will be needed

A 0 016 M of an acid solution in benzene is dropped on a water surface the benzene evaporates and the acid forms a monomolecular film of solid type What volume of the above solution would be required to cover a 500 surface area of water with monomolecular layer of acid Area covered by single acid molecule is 0 2 24 94 x 10 ml B 25 94 x 10 ml Correct Answer 3 67 x 10 3 ml 06

The frequency of radiation emitted when the electron falls from n 4 to n 1 in a hydrogen atom will be Given ionization energy of H 2 18 x 10 18 J atom and h 6 625 x 10 34 Js a 1 54 x 10 5 S 1 c 3 08 x 10 5 S 1 b 1 03 x 10 5 S 1 d 2 00 x 10 5 S 1 2004

In chromite ore the oxidation number of iron and chromium are respectively a 3 2 b 3 6 c 2 6 d 2 3

3 A mixture of 0 5 mole of CO and 0 5 mole of CO is taken in a vessel and allowed to effuse out through a pinhole into another vessel which has vacuum If a total of A mole has effused out in time t show that M A M 1 A 36 where M and M are mean molar masses of the mixture that has effused out and the mixture still remaining in vessel respectively

Electrolysis of an acetate solution produces 57 ethane according to the Kolbe reaction 2CH COO C H 2CO 2e What volume of ethane is produced at 27 C and 720 mm Hg if a current of 0 4 ampere were passed through the solution for 8 hours and the electrode reaction is 75 efficient 1 2 7L 2 1 35 L 3 1 16 L 4 0 65 L

In victor Mayer s method 0 2 g of a volatile compound on volatilisation gave 56 mL of vapour at STP Its molecular weight is 1 40 2 60 3 80 4 120

2 9 10 yr 19K 40 A 10 yr 20 40 18 Ar40 Ratio of atoms of Ar to K in a rock sample is 3 10 Calculate age of rock sample assu that source of Ar is radioactive decay of K40 only and no Ar was present at the ti formation of rock

of its low solubility and K Cr O7 is separated What weight of chromate ore having 20 purity should be used to produce 1Kg potassi dichromate crystals A 3 81kg C 2 80kg B 1kg D 7 62kg The composition of air which is passed in Isten is 80 N and 30 For th 294

108 510 mg of a liquid on vapourisation in Victor Mayer s apparatus displaces 67 2 cc of dry air at NTP The molecular weight of liquid is 1 130 2 17 3 1700 4 170

15 A vessel of volume 8 0 x 103 m 3 contains ideal gas at 300 K and 200 kPa The gas is allowed to leak till the pressure falls to 125 kPa Calculate the mole of gas leaked out if temperature remains constant Assume ideal nature

Acetic acid dissociates 1 3 What will be the pH of N 10 solution of the acid A 2 066 B 1 300 C 2 086 D 2 886

3 Assuming the same pressure in each case calculate the mass of hydrogen required to inflate a balloon to a certain volume V at 100 C if 3 5 g helium is required to inflate the balloon to half the volume V at 25 C

3 a Water gas a mixture of H and CO is an important industrial fuel produced by the reaction of steam with red hot coke essentially pure carbon Write the expression for the equilibrium constant for the reversible reaction 0 C s H O g CO g H g AH 131 30 kJ Assume that equilibrium has been established and predict how the concentration of each reactant and product will differ at a new equilibrium if 1 more C is added 2 H O is removed 3 CO is added 4 the pressure on the system is increased 5 the temperature of the system is increased

C V C V2 V V net Now T Cnet V P of solute containing 6 g of non volatile solute in 180 g of water is 20 Torr mm of Hg If 1 mole of water is further added in to the V P increses by 0 02 Torr calculate V P of pure water molecular wt of non volatile solute m 54 g mol RT

The initial pressure of COCl is 1000 torr The total pressure of the system becomes 1500 torr when the equilibrium COCI g attained at constant temperature of a reaction 1 1500 3 2500 prze 2 1000 4 500 CO g Cl g is The value of K

5g of pure MgO obtained by reaction of metallic magnesium with oxygen contains 3g of Mg Again 8 5 g of pure MgO obtained by heating MgCO contains 5 1g of Mg Show that these results are in accordance with the law of constant proportions

32 Calculate the Gibb s energy change when 1 mole of NaCl is dissolved in water at 25 C Lattice energy of NaCl 777 8 KJ mol AS for dissolution 0 043 KJ mol and hydration energy of NaCl 774 1 KJ mol 1 8 114 KJ mol 2 11 4 KJ mol 3 5 4 KJ mol 1 4 4 5 KJ mol 1

graphite 2 g CO g AH 393 kJ mol H O H g 1 2O2 g AH 286 kJ mol C H OH 30 g 2CO g 3H O l AH 1368 kJ mole The AH of C H OH will be 1 689 kJ 3 138 kJ 2 344 5 kJ 4 276 kJ

67 For the reaction 2NO 2H N 2H O half life is found to be 90 sec and 10 sec when the initial pressures are 200 atm and 600 atm respectively The order of reaction is a 1 b 3 2 c 2 d 3

a Derive a relationship between molality molarity of a solution in which w g of solute of molar mass M g mol is dissolved in W g solvent density of resulting solution d g ml 1 4 g mL b Calculate molality of 1 2 M H SO4 solution If its p

For a hypothetical reaction nx MY value of AH 133 kJ and AS 145 JK Calculate i the value of AG at 700 K ii value of AS surr and AS univ 16 43 JK the Ans i 14 5 kJ ii 161 43 JK

A 6 90 M solution of KOH in water has 30 by weight of KOH Calculate density of solution Let V 1 It then moles of solute 6 9 wt of solute 6 9 56 g 100

24 Oxidation state of Fe in Fe3O4 is 1 1 1 IN N 2 2 3 2 2 2 3 4 4 2

74 If the uncertainity in position and velocity is same then the value of Ax is 1 Ax 3 Ax h m 2 2m 2 AX 4 Ax 2 m h VAT

5 100g of a radioactive substance is disintegrated to 40g in 10 minutes The time taken to disintegrate 100g of the same substance to 6 4g is a 15 minutes c 25 minutes b 20 minutes d 30 minutes