Physical Chemistry Questions

The standard state Gibbs free energies of formation of C graphite and C diamond at T 298 Kare AG C graphite 0kJ mol 4G C diamond 2 9 kJ mol The standard state means that the pressure should be 1 bar and substance should be pure at a given temperature The conversion of graphite C graphite to diamond C diamond reduces its volume by 2x10 6m mol If C graphite is converted to C diamond isothermally at T 298 K the pressure at which C graphite is in equilibrium with C diamond is Useful information 1 J 1 kg m s2 1 Pa 1 kg m s 1 bar 105 Pa 2

Match Column l Compounds A Tetrachloroethene B NO C NO D CO P Q R Column II Characteristics Liquefaction of it is due to London forces only Used as a solvent for dry cleaning At least one atom is sp hybridized Bond order of at least one bond is greater than 2 S T Odd electron species

The vapour pressure of pure benzene at a certain temperature is 200 mm Hg At the same temperature the vapour pressure of a solution containing 2g of non volatile non electrolyte solid in 78g of benzene is 195 mm Hg What is the molecular weight of solid A 50 C 85 B 70 D 80 A A

Vander waal s gas equation may be expressed as B C Vm V m Where Vm molar valume of gas If B 0 105 L mol and C 4 10 4 L mol 2 at 127 C the value of Vander waal constant a in atm L mol 2 is R 0 08 L atm K mol Z 1

b A useful commercial source of magnesium is sea water where Mg aq is 0 054 mol dm 3 The magnesium is precipitated from solution by adding calcium hydroxide Mg2 aq Ca OH s Ca aq Mg OH s i Write an expression for the Ksp of Mg OH 2 including its units ii The numerical value for Kp is 2 00 x 10 11 Calculate Mg aq in a saturated solution of Mg OH 2 iii Hence calculate the maximum percentage of the original magnesium in the seawater that this method can extract

4 X 1 Calculate the mass of CaO formed by heating 50g of CaCO3 in the reaction CaCO3 CaO CO2 Question Type Single Correct Type 1 28g 2 56g English Review 3 100g

Consider the following equilibria B s I A s II 2A C B 1 III A s B g IV A g B g Which of the above will not be disturbed by increase in pressure A I and IV C II III and IV B I II and IV D IV only

4 X 1 Find the uncertainty in position of an electron if the uncertainty in velocity is 50 of uncertainty in position Question Type Single Correct Type 1 2 3 h 3 m 1 414 h 7m English h m Review

Q2 Consider the following parallel reaction A 120 B a Write the expression for d B dt at time t when A is the initial concentration of A

USE OF FREE ENERGY IN CHEMICAL EQUILIBRIA The alkalinity of water is due to the presence of ans Hydroxyl ions All the above Carbonate ions Bicarbonate ions

3 1 2 AAB C gas 4 1 2 both Ca OH milky H O gas E Then incorrect statement is 1 A is NaHCO 2 B is metal carbonate which is soluble in H O 3 pH of aquous solution of both A and E is 7 61 3 A TIET 1 2 3

A cylinder filled with 0 04 mol of an ideal gas 60 compressed reversibily from 350 ml to 75 ml at a constant temperature of 37 C As it does so it releases 208 J of heat The values of q and w for the process will be R 8 314J mol K In 7 5 2 01 1 q 208 J w 208 J 2 q 208 J w 208 J 3 q 208 J w 208 J 4 q 208 J w 208 J 0 04 3 350 ml 75 ml for ff at f 9 EFT R 8 314J mol K In 7 5 2 01 20 J 1 q 208 J w 208 J 2 q 208 J w 208 J 3 q 208 J w 208 J 4 q 208 J w 208 J

Pressure versus temperature graph of the ideal gas at constant volume V of an ideal gas is shown by a straight line A Now mass of the gas is doubled and the volume is halved then the corresponding pressure versus temperature graph will be shown by the line 1 A PA V 2 B 4 none of these 41 The A 1 A 3 C en a na ten 2 B 4 T

b Calculate the temperature at which liquid Zn would form on quenching the gas Reaction is ZnO s CO g Zn g CO Given AG 46 500 27 0 T Cal The vapour pressure of liquid zinc is given by the relationship log P Zn atm 0 775 log T 11 24 6850 T

wo organic liquids A and B have vapour pressure p and p at 80 C in their pure states A mixture of the two has normal boiling point 80 C and shows ideal behaviour It has mole raction of A 0 16 If p p 472 mm then p will be in mm of Hg Round off your answer to nearest integer

One faraday of electricity was passed through NaCl 1 CaCl2 1 AlCl3 1 kept in three different vessel using platinum electrode The ratio of moles of Na Ca and Al deposited at respective electrodes will be 01 2 3 03 2 1 26 3 2

A cylinder contains 0 32 g of oxygen The same volume of an unknown gas X under similar conditions of temperature a pressure weighs 0 26 g The gas X is known to contain only carbon and hydrogen atoms in the ratio of 1 Identify the gas X Ans C

Ex 32 In the decomposition of H O2 at 300 K the energy of activation was found to be 18 kcal mole while it decreased to 6 kcal mole when the decomposition was carried out in the presence of a catalyst at 300 K How many times is the catalysed reaction faster than the uncatalysed one ies of activation when the reaction

Find the total negative or positive charge on a 2 g silver coin The atomic mumber and atomic mass of silver is 47 and 107 9 u respectively Given bungadro s number is 6023 x 10 ml

The half life of a radioactive minutes The time interval stages of its 33 and 67 decay is Question Type Single Correct Type 1 40 minutes 2 20 minutes element is 20 between the 3 30 minutes

The spin only magnetic moment in BM and 62 geometry of Cu NH are 1 2 83 Tetrahedral 2 1 73 Tetrahedral 3 2 83 Square planar 4 1 73 Square planar A compound of vanadium chloride has spin only a Cu NE surfafa 1 2 8 2 1 7 3 2 8 4 1 7

500 ml of 2M hcl and 100 mL of 2M h2 so4 and 1 gram equivalent of monoaci dic alkali are mixed together 30 Ml of th is solution need 20 mL of 143 g Na2CO 3 xh20 in 1 L solution Calculate water o f crystallization of Na2CO3 xh20

4 The ionization constant of a weak electrolyte is 25 x 106 while the equivalent conductance of its 0 01 M solution is 19 6 S cm eq The equivalent conductance of the electrolyte at infinite dilution in S cm eq will be 1 250 2X202 2 196 4 384

SolveLancer Test Which of the following can be used to clean turbidity of water as it is does not increase toxic ions in water SolveLancer Test a Alum b Vinegar c Calcium salts d Powder of kernel of tamarind seeds

2 What is the equilibrium mole fraction of component A in both the liquid and vapor phase of a 2 component 2 phase system at 90 C The following information is known VA RT 10 PT Henry s Constant of A 1 x 10 bar 90 C Partial Pressure of A 20 bar Partial Pressure of B 10 bar

1 Ca 2 Fe 3 Qu 125 Arrange the following in the order of their decreasing electrode potentials Mg K Ba Ca 1 K Ba Ca Mg82 Ba Ca K Mg 3 Ca Mg K Ba 4 Mg Ca Ba K 136 The voltage of a cell Mg 2e Mg s E Cu 2e Cu s E standard EMF of the 2 4 some times positive and some tim 126 For the cell reaction to be spontaneous the EMF of the cell should be

The bromination of acetone that occurs in acid solution is represented by this equatio CH3 COCH3 aq Br2 aq CH3 COCH Br aq Br a These kinetic data were obtained for given reaction concentrations Initial concentrations M CH COCH 0 30 0 30 0 30 0 40 Br H 0 05 0 10 0 10 0 05 3 1X10 4 0 05 0 05 0 10 0 20 Initial rate disappearance of Br Ms 5 7X10 5 5 7X10 5 1 2X10 4 Based on these data the rate equation is a Rate k CH3COCH 3 H b Rate k CH COCH3 Br c Rate k CH3COCH3 Br H d Rate k CH3COCH3 Br H

Color green Stock 10 0m g 1 82 or colding 11 If you wanted to create a 1 500 dilution of the original stock solution how would you do this Be sure you write out a your procedure including b which solution from your serial dilution you would use as a starting point c how many milliliters of the solution you would use and d how many milliliters of water would be added to create your dilution

For a dilute solution containing 3 2 g of a non volatile non electrolyte solute in 100g water the elevation in boiling point at 2 atm pressure is 3 C Assuming concentration of solute is much lower than the concentration of solvent the vapour pressure mm of Hg of the solution is Take K 0 76 K mol kg a 724 c 742 b 740 d 718

Prove the equilibrium condition of TA TB for subsystems A and B of an isolated total system HINT Use that the equilibrium condition is the state with maximum entropy For thermal equilibrium that would be at constant volume Use ideal gas and the fact that U UA UB constant

ALLEN 1000 mL 1 M CuSO aq is electrolysed by 53 9 65 amp current for 100 sec using Pt electrode Which is incorrect statemenet 1 Blue colour intensity decreases during electrolysis 2 Blue colour intensity remains constant if Cu electrode used 3 pH of solution is 8 after electrolysis 4 At anode O gas liberated during electrolysis Which of the fo 1000 ff 1 M CuSO aq 9 65 A 100 g 1 2 Cu n fa feer Tel 8 1 4 440 324 pH

The energy of the second Bohr orbit in the hydrogen atom is 3 41eV The energy of the second Bohr orbit of He ion would be uestion Type Single Correct Type 1 2 0 85 eV 13 64 eV

KMnO4 reacts with oxalic acid according to the equation 2MnO4 5C 02 16H 2Mn 10CO 8H O here 20 mL of 0 1 M KMnO4 is equivalent to 1 20 mL of 0 5 M H C O4 2 50 mL of 0 1 M H C O4 3 50 mL of 0 5 M H C O4 4 20 mL of 0 1 M H C O4

s pd f e Decreasing effective nucical ii Within a shell the effective nuclear charge decrease with increase in the azimuthal quantum of the electron Isrladire un ns np nd nf 1 0 7 1 1 2 1 3

ALLEN Number of moles of MnO required to oxidize 87 one mole of ferrous oxalate completely in acidic medium will be 1 7 5 moles 2 0 2 mole 3 0 6 mole 4 0 4 mole of fi fe fe MnO STERE arit 1 7 5 2 0 2 3 0 6 4 0 4

A solution contains 0 1 M NaCl 0 01 M NaBr and 0 001 M Nal Solid AgNO3 is 08 08 21 JR IIT CO SC MODEL A JEE ADV WAT 14 C gradually added to the solution and its addition does not change the volume of soluti KAgCl 100 KAgBr 103 K Agl 10 17 Choose the correct statement 3 Agl precipitates first B The maximum which can be maintained in the solution so that only AgI is precipitate is 10 M When the precipitation of AgCl just starts 1 in the solution is 10 M DW When the precipitation of AgBr just starts 1 in the solution is 10 M

The energy required for the excitation of 1 10 liter of hydrogen gas at one atmosphere pressure and 298K to the first excited state of atomic hydrogen approximately B DE of H 436 KJ mole is A 98 56 KJ B 108 KJ C 76 KJ D 126 25 KJ

anthanide contraction means A Contraction of atom of lanthanum element due to poor shielding of d subshell electron B Contraction of atom of lanthanum element due to high shielding of d subshell electron C Contraction of atom of elements after lanthanum due to poor shielding of f subshell electron D Contraction of atom of elements before lanthanum due to poor shielding of f subshell electron

If S 0 50 SO 1 2O SO3 SO3 H O H SO4 AH 298 2 kj AH 98 7 kJ AH3 130 2 kJ H 1 2O2 H O AH4 287 3 kj Then the enthalpy of formation of H SO4 at 298 K is 814 4 kJ 650 3 kJ

4 dil KMnO4 0 5 N solution of a salt placed between two 81 platinum electrodes 20 cm apart and of area of cross section 4 cm has a resistance of 25 ohm Calculate the equivalent conductance of the solution 1 1 0 2 ohm cm eq 2 200 ohm cm eq 3 400 ohm cm eq 4 10 000 ohmcm eq In the following gaseous reaction 82 4 KMnO 4 cm men HR f gist and den farer 25 fe facrari guit Na faca 1 0 2 ohm cm eq 1 2 200 ohm cm eq 3 400 ohm cm eq 4 10 000 ohm cm eq fa tefta fufa 2A4B C BE

If ao be the radius of first Bohr s orbit of H atom the de Broglie s wavelength of an electron revolving in the third Bohr s orbit will be B 4 D None of these A 6 26 o A A You Missed

There are 10 identical containers of vol ume V each of them have an ideal gas at a same temperature t the first contai ner has a pressure of 1 ATM the secon d one has a pressure of 2 ATM 3rd has pressure of 3 ATM and so on the 10th c ontainer has a pressure of 10 ATM if all the 10 containers are connected by a th in tube then what will be the final press ure in ATM

The fraction of current carried by each ion in solution is equal to the ratio of conductivity of the ion in solution to the total conductivity of solution If in a solution which is 0 1 M in Na SO4 and 0 01 M in H SO4 assume complete ionisation Given Am of Na H and SO2 are 50 1 S cm mol 1 349 8 S cm mot and 160 S cm mor respectively Select the correct statement A The fraction of total current carried by Nat is more than that of H B The fraction of total current carried by H is more than that of SO2 C The fraction of total current carried by SO 2 is more than that of Nat D The fraction of total current carried by each ion is in order SO 2 Na H

A 1 0 mol of Ideal gas initially at 10 atm and 300K is allowed to expand isothermally to 1 0 atm Calculate the net work done by the system P V diagram is given P 1 1247 1 J 3 1247 1 J 10atm S W 5atm rev W V 1atm 2 3741 3 J 4 3741 3 J

Br 1 Mg ether NO A 1 CO 2 H O Product B is 1 3 Nitro benzoic acid 2 3 Nitro benzaldehyde 3 3 Amino benzoic acid 4 3 Amino benzaldehyde What in the B 64

Which statement is NOT true A The carbon adjacent to a carbonyl group can form a resonance to stabilize a carbanion intermediate B A carbonyl carbon can be made less electrophilic by a nearby metal ion C The carbon adjacent to an imine can form a resonance to stabilize a carbanion intermediate D An adjacent carbonyl group can promote decarboxylation of an keto acid by promoting the breaking of a carbon carbon bond

Consider two reactions at 27 C 1 A B I order kinetics II X Y Zero order kinetics If both A X each having initial concentration 0 1M sa half life period Then find ratio of rate constants for I II K K In2 0 7 reactions

Consider the two first order reaction with rate constants k and k M N K 2 0 10 s 1 N M K 6 0 10 s 1 If 1 mole of M and 3 mole of N are allowed to mix in one litre vessel to attain equilibrium Equilibrium concentration of M in mol L 1 is Correct answer 3

Consider the reactions given below On the basis of these reactions find out which of the the algebraic relationship given in options a to d is correct i C g 4H g CH 9 AH a kJ mol 1 ii C graphite 2H 9 CH4 AH y kJ mol 1 1 x y 2 x 2y 3 x y 4 x y

Comprehension VII of CdS 8 x 102 Kp of ZnS 1 x 1021 K of H S 1 x 10 Which metal sulphide is precipitated first when H S is added A ZnS C Both at the same time B CdS D Both do not form pp