Physical Chemistry Questions

How many coulombs of electricity are required for the oxidation of 1 mole of H O to O 1 9 65 x 104 C 2 4 825 x 105 C 4 1 93 x 104 C 3 1 93 x 105 C

A sample of KClO3 on decomposition yielded 224 mL of oxygen gas at NTP Calculate the weight of KCl produced 1 0 496 g 2 0 9937g 4 0 16g 3 1 986 g

Approximate atomic weight of an element is 26 89 If its equivalent weight is 8 9 the exact atomic weight of element would be 1 26 89 3 17 8 2 8 9 4 26 7

Estimate the lowering of vapour pressure due to the solute glucose in a 1 0 M aqueous solution at 100 C a 10 torr b 18 torr c 13 45 torr d 24 torr

VILLUSTRATION 16 The rate of the chemical reaction doubles for an increase of 10K in absolute temperature from 298K Calculate E

The compound exhibiting maximum value of equivalent conductance in a fused state is 3 MgCl 4 BeCl SrCl 2 CaCl

The volume occupied by 7 23 1023 molecules of carbon dioxide and 3 01 x 1023 molecules of Argon at 0 C and 1 atm pressure is a 38 mL c 3 8 x 104 mL b 3 80 L d 3 8 x 103 mL

Problem 5 Calculate the number of molecules present in 350 cm of NH3 gas at 273 K an 2 atmosphere pressure

1 NH C During electrolysis of water cost of electricity for the production of X litre H at NTP at cathode is Rs X then cost of electricity for the production X litre O gas at NTP at anode will assume 1 mole of electrons as one unit of electricity 2x 2 4X 3 16X 4 32X

1 An aqueous solution of 6 3g of oxalic acid dihydrate is made 13 upto 250 mL The volume of 0 1 N NaOH required to completely neutralise 100mL of this solution is 2 20mL 4 4mL 1 40mL 3 10mL 1

A container contains O and N in equal molar concentration at same temperature what is the corre statement about the average molar kinetic energy of the two gases 1 Depends upon volume 2 KEN KE0 KE 02 4 KEN KEN 3 KEN KE02 1 2

A standard hydrogen electrode has zero electrode potential because 1 Hydrogen is easiest to oxidize 2 This electrode potential is assumed to be zero 3 Hydrogen atom has only one electron 4 Hydrogen is the lightest element

For the reaction 2H O 2H O O the rate equation is given as rate k H O T 1 alkaline medium The unit of rate for this reaction is 2 a mol L S c mol L S 1 b mol L s 1 d mol L s 1

For radial function angular function correct option is are A R r determine size of an orbital B angular function determine energy C R r contains n m only D q q contains m

Example 27 What is the temperature coefficient of the reaction if the rate grows 15 6 times when the temperature is increased by 30 K

1 1 point Round off 563 757 to four significant figures Write your answer with four sig figs in a standard number format and using scientific notati 563 757 standard format scientific notation

An aqueous solution of CuSO4 measuring 1 L was electrolysed till the pH of the solution was found to be 1 Then the amount of Cu deposited and the volume of gase evolved at STP are respectively Cu 63 5 g mol

C 50 g of 20 M NaOH dsoln 1 g ml D 50 g of 5m NaOH An organic compound is burnt with excess of O to produce CO g and H O which results in 25 volume contraction Which of the following option s satisfy the given conditions A 10 ml C3H8 110 ml 0 C 10 ml C3H8O 50 ml 0 B 20 ml C HO 80 ml O D 40 ml C H O4 60 ml 0 A sample of H O solution labelled as 56 77 volume has density of 530 g L Mark the correct option s representing concentration of same solution in other units Solution contains only H O and H O

For a reversible process at T 300K the volume is increased from V 1L to V 10L Calculate AH if the process is isothermal i 2 4 98 kJ 4 11 47 kJ 1 11 47 kJ 30

13 For an electron to have the same de Broglie wave length as that of a Deuteron its velocity should be times that of Deuteron 1 1836 2 1 1836 3 3672 4 1 3672

ALLUSTRATION 10 Sucrose decomposes in acid solution into glucose and fructose according to the first order rate law with t 2 3 00 hours What fraction of the sample of sucrose remains after 8 hours

34 When Hgl is added in KI solution The freezing point of solution 1 increases 2 decreases 3 Remains unchanged 4 Can t predict wol sv

104 For the reaction H g 1 2O g H O l AC 7 63 Cal deg A H 5 68 3 kCal what H25 C will be the value in kCal of AH at 100 C 1 7 63 x 373 298 68 3 2 7 63 x 10 373 298 68 3 3 7 63 x 10 3 373 298 68 3 lots H 4 7 63 x 373 298 68 3

22 An aqueous solution of Na SO4 in water is electrolysed using Pt electrodes The products at the cathode and anode are respectively a H2 SO 2 b O NaOH c H 02 enosups to d O2 SO2 da II a ot the cathode and O g a

The specific conductance of saturated solution of silver chloride in pure water at 298 K is 1 26 x 10 6 ohm cm higher than that of water used The equivalent conductances at infinite dilution of AgNO3 HNO3 and HCl at this temperature are 132 8 421 2 and 426 9 ohm cm1 respectively Calculate the solubility of AgCl at 25 C Ans 0 001314 g litre

Consider the following reaction sequence Sg s 80 g 8SO g 2SO g O g 2SO3 g How many grams of SO are produced from 1 mo Sg 1 1280 g 2 960 g 3 640 g

2 3 2 Suppose the elements X and Y combine to form two compounds XY and X Y When 0 1 mole of XY2 weighs 10 g and 0 05 mole of X Y weighs 9 g the atomic weights of X and Y are a 40 30 c 20 30 b 60 40 d 30 20

py change for one mole of an ideal gas in an isothermal process at 400 K is 2 8 Cal k mole Given In2 0 7 If process is carried out in a single stop then work done is 600 Cal If process is carried out in a single step then work dono is 1120 Cal Enthalpy is constant for the process If the above process is carried out in vacuum then entropy change is zero CODE

2 24 A solution of weak acid HA was titrated with base NaOH The equivalence point was reached when 36 12 ml of 0 1 M NaOH has been added Now 18 06 ml of 0 1 M HCl were added to titrated solution the pH was found to be 4 92 What will be the pH of the solution obtained by mixing 10 ml of 0 2 M NaOH and 10 ml of 0 2 M HA N u H NAA Hce 18 06X0 10 va 20 MA

x24 is a radioactive substance and it decomposes by a decay into stable pb306 The half life of decay of X into Pb is 138 6 days If 1 mole of X is placed in a closed tube then in 69 3 days the amount of a particle in moles accumulated in the tube is approx O 1 mole O 06 moles O 2 moles O 24 moles

451 P The vapour pressure of pure A is 10 torr and the same temperature when 1 g of B is dissolved in 20 gm of A its vapour pressure is reduced to 9 0 torr If the molecular mass of A is 200 amu then the molecular mass of B is 1 100 amu 3 75 amu 2 90 amu 4 120 amu

At 300 K the two solutions of glucose A and B with respective concentrations 0 1 M and 0 01 M are separated by semipermeable membrane How much external pressure need to be applied and on which solution so as to preven osmosis 1 0 2463 atm pressure is applied on solution B 2 2 217 atm pressure is applied on solution A 3 0 0246 atm pressure is applied on solution B 4 0 0217 atm pressure is applied on solution A

Molarity of 29 W density is 1 22 g ml is 1 1 8 M 29 1000 X 98 14 75 2 3 6 M 3 2 4 M 4 1 2 M 29 98 H SO4 solution whose NCERT Pg 23 1 22 18 18000x10 122

In which molecule ion central atom has 3 formal charge 1 0 3 NO 2 N 4 all

Calculate the total pressure in a 10 litre cylinder which contains 0 4 g of helium 1 6 g of oxygen and 1 4 g of nitrogen at 27 C Also calculate the partial pressure of helium gas in the cylinder As sume ideal behaviour of gases Given R 0 082 li tre atm K 1 mol 1

4 Figure shows wave fronts in still water moving in the direction of the arrow towards the interface PQ between a shallow region and a deep denser region Which of the lines shown may represent one of the wave fronts in the deep region P shallow deep IV III II I Q

Question A 0 141g sample of a phosphorus containing compound was digested in a mixture of HNO3 and H SO4 which resulted in formation of CO H O and H PO4 Addition of ammonium molybdate yielded a solid having the composition NH4 3 PO4 12 MoO3 The precipitate was filtered washed and dissolved in 50 0 mL of 0 20M NaOH 56 57 58 NH4 3PO4 12 MoO3 s 260H HPO 2 12M002 14H O 3NH g After boiling the solution to remove the NH3 the excess NaOH was titrated with 14 1 mL of 0 174M HCI The reacted milli moles of NaOH with solid having composition NH4 3PO4 12 MoO3 is A 7 55 B 5 75 C 6 65 D 8 25 Produced mole of NH3 is A 7 62 x 10 3 B 8 71 x 10 4 C 6 85 10 3 The percent of phosphorous in the given sample is B 5 56 A 3 36 C 6 38 D None of these D 7 25

If you add a 120 C platinum piece with a mass of 2 34 g c 0 126 J g C to 100 g of 5 2 C water in a calorimeter that will absorb no heat What is the final temperature of the water

a In non reacting condition O Valency factor Total number of positive charge or negative charge present in the compou Solved Examples e 5 Na CO3 Fe SO4 3 FeSO 7H O

9 Heat of formation of benzene assuming no resonance Given that BE C C 83 kcal BE C C 140 kcal BE C H 99 kcal Heat of atomisation of C 170 9 kcal Heat of atomisation of H 104 2 kcal will be 1 39 kcal 3 1263 kcal 2 75 kcal 21 kool

a 26 93 J K D For a perfectly crystalline solid C p m molar entropy at 20 K is a 0 42 J K mol aT where a is constant If p m 1s 0 42 J K mol at 10 b 0 14 J K mol c 1 12 J K mol d zero

What is the ApH final inital for 1 3 2 3 stages of neutralization of 0 1 M CH COOH with 0 1 M Na 1 2log 2 2 2 log 3 4 2 log 2 3 3 2 log 1 4

31 The emf of the ceil Pt H HA HC H Pt is 0 295 V Dissociation constant of the acid HA 0 01 M IM 1 atm 1 1x 104 3 1 x 10 2 1 x 10 6 4 1 x 10 5

At 30 C K for the dissociation reaction SO CL g SO g Cl g is 2 9 x 10 2 atm If the toal pressure is 1 atm the degree of dissociation of SO Cl is

For the decomposition N O N O 1 2 O the initial pressure of N O5 and after 20 s the pressure of reaction mixture becomes 133 mm Calculate the rate of reaction in terms of a change in atm s and b change in molarity s Given that reaction is carried out at 127 C is 114 mm 114 N O N O 1 2 02 2 g

Half liter of perhedral releases V liters of oxygen at 1 atm and 273K The value of V 50

ATOMIC STRUCTURE In hydrogen atom the kinetic energy of electron is 3 4 eV The distance of that electron from the nucleus 2 0 529A 4 21 16A 1 2 116A 3 1 587A

upto 2 10 electrons 4 6 electrons A d orbital can accomodate 1 5 electrons 3 2 electrons

The absolute value of enthalpy of a system cannot be determined experimentally According to the definition

49 What is the IUPAC name for the following compound a 5 methylcyclohexene 1 methyl 3 cyclohexene c CH3 b 4 methylcyclohexene d 1 methyl 4 cyclohexe