Physical Chemistry Questions

hich of the following statement s is are correct In electrolysis the amount of mass deposited or liberated at an electrode is inversely proportional the amount of electricity passing through the electrolyte The object to be electroplated is taken as anode electrode When electric current is passed through copper sulphate solution copper gets deposited to the ectrode connected to the negative terminal of the battery and i only and s only m only

1 Indicate if the following electron donor electron acceptor pairs represent potential energy reactions for bacterial growth Assume all reactants and products are at unit activity except that pH 7 e donor a ferrous iron Fe b acetate CH3COO c water H O d hydrogen H e acceptor nitrate NO3 sulfate SO4 ferric iron Fe nitrite NO2 energy rxn Yes or No

The elements A B C D E and F have at omic numbers 19 16 10 12 17 and 11 respectively Answer the following a I dentify the strongest non metal b Name the alkaline earth metal c Name the elements which have the s ame valency d Identify the elements that have the s ame number of valence electrons e State the formula of the compound f ormed between the elements B and F

A unit cell has one atom on each corner of cube and two atoms completely inside the cube at one of it s body diagonals if volume of unit cell is 5x10 24 cm and density of element is 15 gram cm The number of atom preset in 150 gram of element is xx1024 Find x Avogadro number 6x10

One mole of an ideal gas is carried through the reversible cyclic process as shown in figure The max temperature attained by the gas during the cycle 7 a mis12 b c 6R 49 12R 12 49R d None of these saibome STIL on babiber s 4 bar P 1 bar B 1 litre 2 litre

1 g of a weak monobasic acid MW 100 when dissolved in 100 g of liquid A MW 100 increases the boiling point from 80 C to 81 C at 760 mm of Hg The vapour pressure of liquid A at 90 C is 850 mm of Hg Degree of dissociation of the monobasic acid is 0 189 at 90 C Enthalpy of neutralization of a strong acid with strong base 57 3 kJ equivalent

A complex is composed of one chromium ion three bromides and six water molecules Upon addition of excess AgNO3 1 0 g aqueous solution of the complex gave 0 94 g of AgBr The molecular formula of the complex is Atomic weight Cr 52 Br 80 Ag 108 O 16 and H 1 A Cr H O 6 Br3 C Cr H O 4Br2 Br 2H O B Cr H O sBr Br2 H O D Cr H O 3Br3 3H O

required for the titration 1 The compound Fe Fe CN molar mass 324 g mol was subjected to oxidation using KMnO in the acidic medium and the product mixture was found to contain Fe and NO along with the liberation of CO It was found that x g of Fe Fe CN was completely oxidised by 40 ml of 0 63 M KMnO4 The value of 100x to the nearest integer is 5 E

2 Which of the following conditions has a negative entropy Smelting gold at high pressure and high temperature Decomposition reaction of water to hydrogen and oxygen gas A perfectly crystalline material in temperature approximately near zero K An insoluble salt has a zero enthalpy of solution at room temperature

NEED RIGHT ANSWER ONLY DO IF CONFIDENT YOU CAN GET IT A solution contains 1 08x102 M manganese II acetate and 6 47 10 3 M copper II nitrate Solid sodium sulfide is added slowly to this mixture A What is the formula of the substance that precipitates first formula B What is the concentration of sulfide ion when this precipitation first begins S M

molar mass of the Temperature and pressure in Chandigarh are respectively 35 C and 740 mm Hg whereas at Shimla these are 10 C and 710 mm Hg Calculate the ratio of densities of air at Chandigarh d and at Shimla d

On moving across a period the atomic size decreases and nuclear charge increases and therefore the force of attraction exerted by the nucleus on the electron in the outermost shell increases The first ionization potentials in eV of Li and Na atoms respectively are Select an answer A B C D 14 6 13 6 13 6 14 6 13 6 13 6 14 6 14 6

47 A gas is collected in flask as shown below a gas 50 mmHg The pressure exerted by the gas when the atmospheric pressure is 0 9 atm is abc mmHg The value of a b c is e g if pressure is 123 mmHg then answer will be 1 2 3 6

A solution contains 0 25 M NaCl and 2 1e 05 M ZnCl2 The available equilibrium data are as follows Zn Cr ZnCl CK 1 01 ZnCl Cl ZnCl CK 1 67 Note The pH of the solution if sufficiently low that you may neglect the hydrolysis of Zn2 The concentration of ZnCl M in the solution is

D Calcium carbonate reacts with HCl to give CaCl and CO according to the reaction CaCO3 s 2HCl aq CaCl aq CO g H O 1 What mass of 20 impure CaCO3 is required to react completely with 250 mL of 0 50 M HCI 1 6 25 g 3 4 75 g 2 5g 4 78 a

Convert these reaction rates to molarity using beers law Reaction rate is 0 013 9 0 0 0002000 10 0 0002000 10 0 0001500 10 0 0002500 10 0 001300 00 0 0001500 00 0 0001000 01 0 0001500 10 E406H 11 12 0 0002000 0 0007501 0 0001000 0 0001500 0 0001500 0 0001500 0 0002500 0 0001500 0 0002000 0 0002000 0 0001500 0 0002000 0 0002500 0 0001500 0 0001500 0 0003000

7 50 mL of 0 5 M oxalic acid is needed to neutralise 25 mL of sodium hydroxide solution The amount of NaOH in 50 mL of the given sodium hydroxide solution is a 10 g c 40 g b 80 g d 20 g oth 1st Ski 2019

The equilibrium constant gives information about which direction of a reaction is favored If the K for the reaction shown below is 1 1 x 107 which compound s is favored 2 H2 g S2 2 H S H S O H and S H

0 1 mole of an ideal monoatomic gas with Cv independent of temperature is made to undergo a reversible cyclic process consisting of the following steps State 1 1 lit 1 atm State 2 1 lit 3 atm State 2 1 lit 3 atm State 3 2 lit 3 atm State 3 2 lit 3 atm State 4 2 lit 1 atm State 4 2 lit 1 atm State 1 1 lit 1 atm Calculate q w and AE for each step and for the complete cycle Comment on ca ICI

In which of the following options the order of arrangement does not agree with the variation of property indicated against it 1 Si Al Mg Na 2 S Se Te O Increasing metallic character Negative electron gain enthalpy

At equilibrium the reaction H Cl 2 HCI has a Ke of 8 0 and contains HCI 2 0 M and Cl 1 0 M What is the equilibrium concentration of the hydrogen gas 2 0 M O 0 5 M 0 25 M 4 0 M

74 The oxidation states of transition metal atoms in K Cr O7 KMnO4 and K FeO respectively are x y and z The sum of a y and is

Pak 77 CAREER INSTITUTE MOTA HAIMITRIN An ideal gas undergoes through following cyclic process 1 2 Reversible adiabatic compression from P V T to P V T 2 3 Reversible isochoric heating from P V T to P V T 3 4 Reversible adiabatic expansion from P V Tato PVT 4 1 Reversible isochoric cooling from PVT to P V T Efficiency of the cycles is A 1 B 1 D 1 Q4 11 Q C 1 78 An ideal gas initially at PV T is expanded isothermally to twice it s volume then compressed at constant pressure to have the original volume V Finally the gas is heated at constant volume to get original temperature what is correct A P V diagram for the process is B Total heat supplied is 0 193 PV C Net work is done by the gas D Interal energy remain same during the who 79 The spontaneity means having the potential to proceed without the assistance of external a hec

a What is electrolysis and State Faraday s laws of electrolysis Mar 14 Mar 15 T S b A solution of CuSO is electrolysed for 10 minutes with a current of 1 5 amperes What is the mass of copper deposited at the cathode Mar 14 Mar 15 T S A P

2 3 2 moles N O4 were introduced in a flask of 10 litre capacity at 350 K At equilibrium 50 of N O4 was found to be dissociated into NO Find out equilibrium constant for the dissociation of N O4 under the given conditions

Two liquids Afp 100mm and B P 200 mm are mixed together in a molar ratio of 2 1 and kept in a cylinder with a piston at such pressure that no vapour is formed initially the piston in now withdrawn slowly while keeping the temperature constant What is the pressure when 1 4 the moles of liquid have vaporized in mm

30 At 298 K the standard enthalpies of formation of H O l and H O are 286 0 kJ mol and 188 0 kJ mol 1 The enthalpy change for reaction 2H O 1 2H O 1 O g will be 1 948 kJ mol 2 196 kJ mol 1 3 196 kJ mol 1 4 948 kJ mol 1

The molar conductance of a strong electrolyte at infinite dilution A tends to a finite value which is above that a higher concentration B tends to a finite value which is below that at higher concentration C tends to zero D tends to a finite value which is equal to that at high concentration

Three bulbs I II and III of volume V litres 2V litres and 3V litres are connected by tubes of negligible volume fitted by stopping valve as shown in fig The bulb I is at 1 atm containing 0 3 mol of H gas at temp 127 C Bulb III contains O2 gas at 77 C and pressure of 2 atm Bulb II is vacuum and maintained at temp 27 C 1 atm VL 0 3 moles of H i 127 C valve a 2VL ii 27 C valve b 3VL 02 gas 77 C iii 2 atm The valve b is opened first and then closed after some time Then the valve a is opened and closed after same time as for valve b The number of moles O2 diffused into bulb II is 0 1 mol The partial pressure in atm of H observed in bulb 1 after diffusion is

How many phases are there in NaCl solutio n I know as per the definition of homogene ous mixtures it would have single phase but sir if we change our perspective and observ e it microscopically then I think it would hav e 2 phases as the salt is solid and water is li quid and both have their own properties the n why we call it single phase So by this way I think there is no such thing as homogeneo us mixture if we talk about it on the basis of Phase because any mixture would surely ha ve atleast 2 phases so sir kindly clarify my c onfusion

13 2 Moles of potassium reacts with cold water to give x Moles of hydrogen and 3 moles of iron reacts with steam to give y moles of hydrogen The value of y 2 x will be Only One Correct Answer Review A 8 O

An engineering student purchased piece of amber from a local shopping mall The amber contained the remains of an beetle Curious to know whether the gem is genuine or not the student takes the sample to the laboratory and determines the concentration of Carbon 14 5730 years After extracting a piece of the trapped beetle with a fine drill instrument analysis reported that the concentration of Carbon 14 is now only 94 If there was 100 Carbon 14 when the beetle was trapped how old is the gem and is it genuine Trivia Amberification is a polymerization process that takes several millions of years The youngest amber is around 16 million years old and can be found in the Dominican Republic 23 million years old genuine O 51 million years old genuine O 23 000 years old counterfeit O 510 years old counterfeit

Given the following thermochemical data 4 B s 3 O2 g 2 B2O3 s 2 B s 03 g B20O3 s 1 What is AH for the reaction 2 03 g 3 02 g OA 1122 kJ OB 284 kJ OC 284 kJ OD 1122 kJ OE 5340 kJ OF 5340 kJ AH 2528 kJ AH 1406 kJ

75 For the disproportionation reaction 2Cu aq Cu s Cu aq at 298 K In K where K is the equilibrium constant is x 10 Given Cut E 0 16 VE Cut Cu 0 52 V 0 025

In a particular system the half life of Lindane undergoing aerobic decomposition is 210 days A contaminated groundwater has a Lindane concentration of 30 ppb The maximum contamination level MCL for Lindane is 0 1 ppb How long does it take for the concentration of Lindane to be below MCL Do you expect that Lindane will have strong adsorption on solid Calculate its BCF knowing that log Kow is 3 38

19 The value of ebullioscopic constant depends upon 1 AHsoution 3 Nature of solute 2 Nature of solvent 4 Freezing point of solution topic with 1 solution of a non volatile non electrolyte substance Ther

63 The shape structure of XeFs and XeO3F2 respectively are A octahedral and square pyramidal B trigonal bipyramidal and trigonal bipyramidal C trigonal bipyramidal and pentagonal D pentagonal planar and trigonal bipyramidal

14 Pressure exerted by a perfect gas is equal to 1 Mean kinetic energy per unit volume 2 Half of the mean kinetic energy per unit volume 3 Two thirds of mean kinetic energy per unit volume 4 One third of mean kinetic energy per unit volume

Consider the reaction between Fe and NCS ions The equilibrium constant for this reaction is 620 4 Calculate the equilibrium concentration of NCS ion in a solution that contains 10 0mL of 0 05 M ferric nitrate in 1M HNO3 2 0mL of 5 0 10 M NaNCS and 8 0mL of distilled water Assume that all the NCS is converted to FeNCS 4 A 6 07x10 8 M B 3 04x10 6 M C 0 M D 1 00 x 10 6

In the plasma membrane Glycolipids are usually situated in O O cannot be predicted it varies according to the cell types O O 1 point O inner leaflet of plasma membrane O outer leaflet of plasma membrane evenly distributed in both outer and inner leaves of plasma membrane

A crystal is made up of particles A B and C A forms fcc packing 8 occupies all octahedral voids and C occuples all tetrahedral voids If all the particles along one body diagonal are removed then the formula of the crystal would be 1 ABC 2 A BC 3 A B C

1 Common salt obtained from sea water contains 95 NaCl by mass The approximate number of molecules present in 10 0 g of the salt is a 10 1 b 1022 c 1023 d 1024

A water sample contains 10 6 M copper It has a pH of 7 5 and a CT CO3 of 7 72 x 10 M Assume that CuCO30 aq is the only important Cu complex Cu CO3 CO3 CUCO3 aq log K 6 77 For the carbonate system at pH 7 5 do 0 06630 a 0 9372 and a2 0 001382 a1 The concentration of Cu2 M in solution is

Which one of the following statements is not true regarding lactose a Lactose C12H22O11 contains 8 OH groups b On hydrolysis lactose gives equal amount of D glucose and D galactose c Lactose is a B glycoside formed by the union of a molecule of D glucose and a molecule of D galactose d Lactose is a reducing sugar and does not exhibit mutarotation

Photoelectric emission is observed from a surface for frequencies v and v of the incident radiation v v If the maximum kinetic energies of the photoelectrons in the two cases are in the ratio 1 k then the threshold frequency vo is given by b a c V2 V1 k 1 kv V1 k 1 d kv V2 k 1 V2 V1 k

Calculate the equilibrium constant for the reaction 3Mg 2Al 3Mg 2Al For Mg 2e Mg k E 2 363 For Al 3e Al k E 1 662 Cr solution is obtained by electrolysis of Cr solution In 500 mL of 0 15 M Cr solution how long would it take to reduce Cr to Cr using a current of 0 158 A The potential of the DKE MgA2 Mg2 9 62 x 10 M Mg ISE ion selective electrode Cell is 0 367V When the Mg solution in the cell is replaced with an unknown Mg solution the cell potential becomes 0 244 V What is the concentration of this Mg solution

7 Consider the following process A B AH kJ mol 1 325 kJ mol 3 525 k l mol 150 3B2C D 125 E A 2D 350 For B D E 2C AH will be AIPMT Mains 2011 2 325 kJ mol 1 175 k

3 The heat of combustion of ethanol into carbon dioxids and water is 327 kcal at constant pressure The heat evolved in cal at constant volume at 27 C if all gases behave ideally is R 2 cal mol K 36 37 Section 2 46 47 Chemistry

Example 7 6 Calculate the acetic acid if its K 1 8 x 105 What would be the degree of ionization if the solution also contains 0 01 M sodium acetate Solution CH COOH aq CH COO aq H aq The degree of ionization of this weak acid can be calculated by the approximate relation V C Ka 1 8 x 10 5 0 02 Now let us calculate the degree of ionization when the solution also contains 0 01 M sodium acetate Sodium acetate being a strong electrolyte would be completely ionized in solution Let x mol L 1 of acetic acid be ionized CH COOH aq CH COO aq H aq 0 02 x M x M x M CH3COONa aq CH3COO aq Na aq 0 01 M 0 01 M 18 x 107 H x mol L CH COO x 0 01 mol L 0 01 mol L 1 x is very small as compared to 0 01 CH COOH 0 02 x mol L 0 02 mol L 1 H CH COO CH COOH K 5 x x 0 01 0 02 x 3 6 x 10 5 H 3 6 x 10 5 M Degree of ionization 0 03 3 x 10 r 3 6 10 5 1 8 x 104 0 02 0 02 Thus it may noted that the degree of ionization of acetic acid has decreased from 3 x 10 2 to 18 x 10 due to the presence of sodium acetate Sodium acetate suppresses the degree of ionization of

1 A buffer is made from the aminium salt of an amine e g R NH3 and the neutral amine e g R NH If the aminium form has a pK of 10 6 and the pH is measured to be 11 1 then what fraction of the compound will be in unprotonated amine amino form Enter your answer as a percent to the nearest ones