Physical Chemistry Questions

31 From the following pairs select the one in which both samples contain same number of atoms 1 2 4 g of O and 4 2 g of N 2 4 4 g of CO2 and 4 6 g of Na 3 1 4 g of H SO4 and 560 mL of SO g at STP 4 6 023 10 molecules of H3PO4 and 7 3 g of HC

Metal can be prevented from rusting by 1 3 Connecting iron to more electropositive metal a case of cathodic protection Connecting iron to more electro positive metal a case of anodic protection Connecting iron to less electropositive metal a case of anodic protection Connecting iron to less electropositive metal a case of cathodic protection Correct Answer 1 Status unattempted

Each question carries 8 marks 6 A What is galvanic cell Explain construction and working of galvanic cell with neat diagram calculate no of electrons are required for the deposition of 23 gm of aluminum

5 Negative deviations from Raoult s law are exhibited by binary mixtures 1 in which the molecules tend to attract each other and hence their escape into the vapour phase is retarded 2 in which the molecules tend to repel each other and hence their escape into the vapour phase is retarded 3 in which the molecules tend to attract each other and hence their escape into the vapour phase is speeded up 4 in which the molecules tend to repel each other and han onog

The correct formula to calculate the hydroxyl 100 concentration of an aqueous solution of NH NO is 1 3 CxK V Kb CxK 1 K W W 2 4 V KwxKb W C K XK a C W

An aqueous solution containing 28 by weight of a liquid A molecular mass 140 has a vapour pressure of 0 200 bar at 37 C Calculate the vapour pressure of pure liquid vapour pressure of water at 37 C 0 100 bar

55 A solution of sucrose molar mass 342 has been prepared by dissolving 68 5 g of sucrose in 1000 g of water The freeqzing point of the solution obtained will be Kf for water 1 86 K kg mol 1 0 520 C 2 0 372 C 3 0 372 C 4 0 570 C

7 At 25 C the vapour pressure of pure methyl alcohol is 92 0 torr Mol fraction of CH OH in a solution in which vapour pressure of CH OH is 23 0 torr at 25 C is 1 0 25 2 0 75 3 0 50 4 0 66

The best indicator with their pH range given for the detection of end point in titration of a weak acid and a strong base is a Methyl orange 3 to 4 b Methyl red 5 to 6 c Bromothymol blue 6 to 7 5 d Phenolphthalein 8 to 9 6

5 In a vessel containing SO3 SO and O at equilibri some helium gas is introduced so that total pres increases while temperature and volume remain the sa According to Le Chatelier s principle the dissociatio SO

Illustration 6 73 150 mL of 0 5 N nitric acid solution at 25 35 C was mixed with 150 mL of 0 5 N sodium hydroxide Solution at the same temperature The final temperature was recorded to be 28 77 C Calculate the heat of neutralisation of nitric acid with sodium hydroxide

Choose the right one Cu S CuS Copper sulphide does not dissolve under the action of either reagent 2M hydrochloric acid o reagent nitric acid because copper ion sulfide ion oxonium ion H concentration is not high enough to that the copper ion sulfide ion concentraion sufficiently decrease increase

What is the maximum number of layers of atoms in close packed planes that will lie within two imaginary parallel planes having a distance between them of 12 R where R is the radius of atom Consider the atoms to be within the parallel planes if their centres are on or within the two parallel planes

When rain is accompanied by a thunderstorm the collected rain water will have a pH value a slightly lower than that of rain water without thunderstorm b slightly higher than that when the thunderstorm is not there

Heat of formation of isobutylene is Given heat of sublimation of carbon is 715 kJ mol and bond energy of H H C H C C C C is 431 410 336 and 606 kJ mo respectively 1 48 kJ 3 26 kJ 2 26 kJ 4 49 kJ

9 The vapour pressure of pure liquid solvent A is 0 80 atm When a non volatile substance B is added to the solvent its vapour pressure drops to 0 60 atm the mole fraction of component B in the solution is 1 0 3 2 0 2 0 25 4 3 0

The rate constant for the decomposition of ethyl chloride is 4 12 10 5 s 1 at 22 3 C If the reaction s activation energy of 249 kJ mol at what temperature will its rate constant be 5 84x10 4 S 1 Answer in celsius

3 At 27 C the vapour pressure of an ideal solution containing 1 mole of A and 1 mole of B is 500 mm of Hg At the same temperature if 2 mol of B is added to this solution the vapour pressure of solution increases by 50 mm of Hg The vapour pressure of A and B in their pure states is respectively 1 600 mm 400 mm 3 300 mm 700 mm 2 400 mm 600 mm 4 200 mm 800 mm

ILLUS Acetic acid associates in benzene to form a dimer 1 65 g of acetic acid when dissolved in 100 g of benzene raised the boiling point by 0 36 C Calculate the Van t Hoff factor and degree of association of acetic acid K for benzene 2 57 C m

Be sure to answer all parts Complete the following precipitation reaction with balanced molecular total io equations Remember to include the proper physical states and charges of ions charge number is not I place the charge number before the charge sign If a not include the charge number in the formula Na S aq ZnSO4 aq Molecular Total ionic Reactants Products Donn

If a stands for the edge length of the cubic systems simple cubic body centred cubic and centred cubic then the ratio if radii of the spheres 3a 2a 2 a 3a 2a a 3a 1 3 a 4 3a 5 a 5

Using van dar Waals equation of state calculate pressure in atm developed by 132 g of CO2 contained in a volume of 6 0 litre at 27 C a 3 6 atm L mol 2 b 400 cm mol R 0 08 L atm k mol

2005 53 The dissociation constant of a weak acid is 1 x 104 In order of prepare a buffer solution with a pH 5 the D 300 Salt Acid ratio should be 1 1 10 3 10 1 2 4 5 4 5 4

Enter your answer in the provided box One of the first steps in the enrichment of uranium for use in nuclear power plan displacement reaction between UO and aqueous HF UO s HF aq UF4 s H O 0 unbalanced How many liters of 4 33 M HF will react with 6 16 kg of UO

50 ml of 0 5 M oxalic acid is needed to neutralize 25 ml of sodium hydroxide solution the amount of NaOH in 50 ml of the given sodium hydroxide solution is 4 20 g 1 10 g 2 80 g 3 4 g

The reaction CO g C s 2CO g has K 5 78 at 1200 K The reaction CO g C s 2CO g has K 5 78 at 1200 K Calculate the total pressure at equilibrium when 4 52 g of CO is introduced into a 10 0 L container and heated to 1200 K in the presence of 2 31 g of graphite Express your answer to three significant figures and include the appropriate units Ptotal 1 70 atm Submit V Correct Part B Previous Answers Ptotal Repeat the calculation of part A in the presence of 0 44 g of graphite Express your answer three significant figures and include the appropriate units A 19 Value atm Review Constants Periodic Table

ILLUSTRATION 2 43 Liquids X and Y form an ideal solution The vapour pressure of X and Y at 100 C are 300 and 100 mm of Hg respectively Suppose that a solution composed of 1 mol of X and 1 mol of Y at 100 C is collected and condensed This condensate is then heated at 100 C and vapour is again condensed to form a liquid A What is the mole fraction of X in A

The enthalpy and entropy change for the reaction Br 1 Cl2 g 2BrCl g are 30kJ mol 1 105 JK mol respectively the temperature at which the reaction will be in equilibrium is 1 300 K 2 285 7 K 3 273 K 4 450 K

3 1 mol of monoatomic ideal gas at 300 K expands from 1 L to 8 L in two different process Process I Reversible adiabatic expansion Process II Irreversible adiabatic expansion against the constant external pressure of 1 atm given 1 atm L 101 J Select the correct statement 1 W Process WProcess I 2 Tflprocess T Process 11 f 11 f final 3 TflProcess 1 IT fl Process II f final I 4 Change in internal energy in process II is less than change in internal energy of process

Enter your answer in the provided box If 37 0 ml of silver nitrate solution reacts with excess potassium chloride solution t precipitate what is the molarity of silver ion in the original solution

6 What is the OH in the final solution prepared by mixing 20 0 mL of 0 050 M HCI with 30 0 mL of 0 10 M Ba OH 2 AIPMT Prelims 2009 1 0 40 M 3 0 12 M 2 0 0050 M 4 0 10 M

Which of the following is an example of liquid dishwashing detergent Question Type Single Correct Type Me 1 1 Me CH 15 N Me Br I Me 2 Me OX SO3Nat 3 C9H19 OO CH CH20 5 CH CH OH

9 Magic number elements are those isotopes of elements 1 In which the number of protons or neutrons is 2 8 20 28 50 82 or 125 2 Which are relatively more abundant 3 Which are unusually stable bus 4 All of these

2x Heat of formation at standard state for CO g H O l and Hydrocarbon C H x are 400 kJ mol 300 kJ mol and 50 kJ mol respectively If heat of combustion of C H2x at standard state is 1450 kJ mol the correct formula of Hydrocarbon is x 2 C3H6 1 C H4 3

in a hypothetical solid C atorns forming cubical closed packed lattice A atoms occupy all tatrahedral void and B atoms occupy all octahedral voids There is no distortion in cop lattice Fraction of body diagonal not covered up by atoms is 1 2 3 076 024 0 08

49 ub N O4 9 2NO g Kp2 2 The degree of dissociations are equal for both the above reactions If their equilibrium pressures are also in the ratio of 4 1 then ratio of Kp to Kp2 is 1 1 2 estel Two equilibrium reactions are taken in different vessel a PCI g PC13 g Cl g Kp us 3 1 4 2 2 1 4 1 1 Medica Div

A sample of H atoms containing all the atoms is some excited state is irradiated with the light of wavelength and atoms get re excited to further higher excited state On removing the light source atoms de excite to the ground state with the emission of radiations The emission spectrum thus obtained consists of ten spectral lines Out of these ten spectral lines seven lines have wavelengths smaller and only two line have wavelengths longer than The orbit number for initial excited state is

2 Two liquids A and B form an ideal solution The vapour pressure of pure A and pure B are 66 mm Hg and 88 mm Hg respectively Calculate the composition of vapour A in the solution which is equilibrium and whose molar volume is 36 1 0 43 0 30 2 0 70 4 0 50

31 Which statement s is are correct Ja All Bronsted bases are also Lewis bases All Bronsted acids are not Lewis acids Most cations are acids and most anions a bases d All Bronsted bases are also Arrhenius bases

1 Volume of one equivalent O2 is 5 6 litre at STP 3 2 When 10 ml H SO4 is added to 10 ml water then total volume becomes 20 ml 3 Generally combustion exothermic reaction reaction is an dic 4 Atomic radius of gallium is less than that of

Enter your answer in the provided box In a titration of HNO3 you add a few drops of phenolphthalein indicator to 50 00 You quickly add 20 00 mL of 0 167 M NaOH but overshoot the end point and the pink Instead of starting over you add 30 00 mL of the acid and the solution turns takes 7 13 mL of the NaOH to reach the end point What is the concentration of th

What mass of aluminum is required to react in order to produce 12 8 g of aluminum oxide according to the following reaction molecular weights MnO 86 94 g mol Al O3 101 96 g mol 4 Al 3 MnO2 3 Mn 2 Al O3

The solubility product of AgI at 25 C is 1 0 10 16 mol L2 The solubility of AgI in 104 N solution of KI at 25 C is approximately 1 1 0 10 16 2 1 0 10 12 3 1 0 10 10 4 1 0 10 8

of Steady State An assumption Approximation is 1 polr Reaction occurs without the formation of intermediates One of the intermediates in the reaction is consumed as quickly as it is generated Equilibrium state is attained at the end of a reaction Catalyst does not accelerate reaction rate

Which of the following statement is 1 point not true for Lindeman approach O O O The bimolecular step does not account for activation energy dependent unimolecular reaction are usually accompanied by a preceding bimolecular step The internal degree of freedom of molecular are not ignored The internal degree of freedom of molecular are ignored

How many total moles of ions are released when the following sample dissolves cor Enter your answer in scientific notation 8 66x 10 6 formula units of Sr HCO3 2 x 10 mol

For a c MK A potass K3A H A solution potassium salt of a tribasic acid a2 az Dissociation constants of acid are K K K h 1 a pH 1 2 pK PK log c az b pH 1 PK PK log c pKw 2 W a2 1 c pH d pH pK pk log c W pK pK log c 2 a1

4 After 20 min the amount of certain radioactive substance disintegrate was 15 16th of the original amount What is the half life of the radioactive substance 1 4 2 6 3 5 4 8

wow of w moales of ethylene no M Law of consination of 1 mole 100 no of 28 moles mass s of 100 28 mass moles of polythere polythene NA molecules 100 NA molecules moles 100 28 100 28 NA X 38 100 100 28 mol niche wala kese hua no of moles of polythene nikal ke uske molar mass se multiply hoga to iven mass avega and vhi qus me puch rha

A pH buffer is a solution that resists changes in pH when acids or bases are added to it typically a solution of a weak acid and its conjugate base What masses of dimethylamine and dimethylammonium chloride do you need to prepare 7 00 L of pH 12 00 buffer if the total concentration of the two components is 0 500 M Mass of dimethylamine 150 1 g Mass of dimethylammonium chloride