Physical Chemistry Questions

oxidising agent react completely with acidified 0 1 M Kl aq then for which of the following oxidising agent equal moles of each oxidising agent will be used to produce one mole of 12 in each case An Question Type Single Correct Type 1 KMnO4 K Cr O7

2 If hydrogen gas is bubbled through water at 20 C then the number of millimoles of H dissolved in 2 litre of water is H exerts a partial pressure of 0 8 bar and Henry s law constant for H2 at 20 C is 69 16 K bar 1 1 29 2 12 9 3 0 129

Two glass bulbs A and B are connected by a small tube of negligible volume having a stopcock Initially the volun of bulb A is 100 ml with some gas while bulb B is empty Upon opening the stopcock the pressure decreased by 60 The volume of bulb B must be 100 mL 150 mL 200 mL 180 mL

A mixture of hydrogen gas and the theoretical amount of air at 25 C and a total pressure of 1 atm is exploded in a closed rigid vessel If the process occurs under dq 0 condition then using the given data answer the questions that follow Given i C 6 3 Cal deg mol ii C 9 3 Cal deg mol AH H O g 57 8 Kcal Take air as 80 N 20 O by volume What will be maximum temperature approx attained if the process occurs in above container A 298 K B 1900 K C 2665 K D 2940 K What will be the final pressure in atm approx A 0 85 B 5 46 C 7 6 D 8 5

When 5 litres of a gas mixture of methane and propane is perfectly combusted at 0 C and atmosphere 16 litre of oxygen at the same temperature and pressure is consumed The amount of heat released from this combustion in kJ AH comb CH 890 kJ mol AH comb C H 2220 kJ mol is NEET Kar 2013 a 32 c 317 b 38 d 477

Colligative properties depend on a The nature of solute particle dissolve in solution b The number of solute particle dissolve in solution c The physical properties of solute particles dissolved in solution d The nature of solvent particles

The ammonia prepared by treating ammonium sulphate with calcium hydroxide is completely used by NiCl2 6H O to form a stable coordination compound Assume that both the reactions are 100 complete If 1584 g of ammonium sulphate and 952g of NiCl 6H O are used in the preparation the combined weight in grams of gypsum and the nickel ammonia coordination compound thus produced is Atomic weights in g mol H 1 N 14 O 16 S 32 Cl 35 5 Ca 40 Ni 59 29

According to the real gas equation Z 1 for an ideal gas and Z is variable for a real gas Suppose in order to easy our calculations we fixed Z 1 for a real gas and for ideal gas Z will become variable Z vs P for an ideal gas will be similar to ZI P P b d K p L P P

A B C at 25 C k 2 5min k 5 5min k3 10 8 min and k 4 7 min The Arrhenius factor is 102 min for each reaction then AB is an endothermic process B C is an endothermic process O Activation energy for the conversion B Overall order of the reaction is 1 A is higher than the activation energy for the conversion B 2 O

Which of the following statements is are correct C Reversible adiabatic process is isoentropic process for irreversible adiabatic compression is greater than zero AS system S for free expension in zero for irreversible is greater than zero AS system surrounding compression isothermal

6 11 2 L H and 11 2 L Cl2 allowed to react at STP and gas produced dissolved in 1 L water The volume of given solution which can be neutralized completely by 500 ml of 0 2 M KOH is 1 100 mL 2 200 mL 4 250 mL 3 500 mL

The accompanying concentration of species A and B for the reaction AB as a function of time The point of inter section of the two curves represents B conc Times a c 2 3 1 2 d Data insufficient tom A b 13 4

The approximate size of the nucleus can be calculated by using energy conservation theorem in Rutherford s a scattering experiment i e Total energy initial Total energy final In 1st experiment radius of a particular nucleus is calculated by the projection of a particle from infinity at a speed v m s Let this radius be the true radius In 2nd experiment the radius calculation for the same nuclei is made by projecting the a particle with five sixth 5 6 of the earlier speed The percentage error involved in the calculation of radius of nucleus in the 2nd experiment is

2 63 For the gaseous reaction A 1 dn A V dt Method I Where C Ca Products the rate may be expressed as dP nA V k Ch olar perts Method II A dt r concentration of A and P is the partial pressure of A t time t and n is the order of reaction The reaction is occurring at constant temperature T 300 K Assume ideal behaviour of gas Select the correct statement s A A k k for any value of n C k k RT when n 0 El 300 Experts k PA B k k when n 1 D k k RT when n 2

Solvelancer Test The formation of AB takes place according to the given reaction A2 B2 2AB 20 kJ The enthalpy of formation of AB is Solvelancer Test a 10 kJ mol b 20 kJ mol c 10 kJ mol d 20 kJ mol

5 One mole of SO was placed in a litre vessel at a certain temperature When equilibrium was established in the 3 reaction 2SO3 the vessel was found to contain 0 4 moles of SO3 The value of equilibrium constant is 2SO 0 O a 0 13 c 0 68 b 0 36 d 0 45

9 25 Options 11 22 3 3 44 0 29 The molar conductance of acetic acid is 40 S em mol If the dissociation constant is 1 x10 mol L then the concentration of acetic acid is ANAL 90 S cm mol ANC 120 S cm mol and AC 430 Sem mol Options 11 1 2 9x 10 mol L 3 400 Sem mol 4 40 Sem mol 9 x 10 mol L 4 The technique in which the liquid boils when the sum of vapor pressure due to organic liquid P and that due to water P becomes equal to the atmospheric pressure P is 1 Sublimation 2 Fractional distillation 3 Steam distillation 4 Evaporation Quention Type MCQ Que101900091278 Optan 11D 100soes Option 210 1504 Opton 310 19095047 Option 4 10 11 Stat Answered Chosen Option 3 Question Type MCQ Question 10 1908891249 Option ID 1908804029 Option 2 10 1908894930 Option 3 ID 1908894931 Option 4 ID 1900804932 Status Answered Chosen Option 3

Ka HA 10 a 3 10 9 TAZI 1 732 x 10 c 8 3 When a salt of weak acid and weak base is dissolved in water at 25 C the pH of the resulting solution will always a be 7 c be less than 7 with 0 05 11 1 b be greater than 7 a b depend upon K and K values lution of 10 M ammonium formate

If 0 224 litre of H gas is formed at the cathode how much O gas is formed at the anode under identical conditions Assume 96500 C as one unit of electricity If cost of electricity of producing x gm Al is Rs x what

Given that Efe2 Fe Fe Fe 0 44V Eg Fe Fe If Fe Fe and Fe solid are kept together then 1 Fe increases 2 Fe decreases 3 Fe Fe remain unchanged 4 Fe decreases 0 77V

AgBr s 2S O aq 3 Ag S 03 2 aq Br aq Given Ksp AgBr 5 10 13 K Ag S 03 2 5 10 3 What is the molar solubility of AgBr in 0 1 M Na2S2O3 A B C D 0 5 M 0 45 M 0 045 M Correct Answer None of these

The wave function of two different orbitals X and Y in Be 3 ion are given by 1 3 2 Z 6 60 e 0 2 ao 1 3 1 2 y y 9 6 47 2 4 0 e 0 2 2zr nao 4x 1 1 2 9 3 4T 1st 3 2 where ap From this we can conclude cose Bohr radius of H atom z Charge number of nucleus r distance from nucle Options 1 Total number of nodal surface is same for both orbitals TT 2 The angular nodal surface of Y orbital will occur at 0 3 Energy of electron in Y orbital is greater than in X orbital 1 vorggo distance of X orbital from nucleus is greater than Y orbital

A solution of F is prepared by dissolving 0 0868 0 0004 g NaF molar mass 41 989 0 001 g mol in 160 00 0 08 mL of water Calculate the concentration of F in solution and its absolute uncertainty Significant figures are graded for this problem To avoid rounding errors do not round your answers until the very end of your calculations F M M

6 Ionization energy of gaseous Na atoms is 495 5 kjmol The lowest possible frequency of light that ionizes a JEE MAINS ONLINE 2014 sodium atom is 3 1 24 x 1015 S 1 4 7 50 x 104 S 1 h 6 626 x 10 34 Js NA 6 022 x 1023 mol 1 3 15 x 10 5 S 1 2 4 76 x 1014 S 1

In an Otto cycle 33 3 air at 1bar and 290K is compressed isentropic ally until the pressure is 15bar The heat is added at constant volume until the pressure rises to 40bar Calculate the air standard efficiency for the cycle Take Cv 0 717 KJ Kg K and Runiv 8 314KJ Kg K 4 57 percent 5 pecent 3 87 percent 8 85 percent

4 T T 58 Calculate the pH on mixing 100 mL of 0 2M HCN with 400 58 25 C mL of 0 05 M KOH at 25 C pK for CN 8 1 4 7 2 9 3 3 5 7 4 8 3 1 4 7 2 9 3 3 5 7 4 8 3 400 mL 0 05 M KOH 0 2M HCN 10 pH pk for CN 8

4 4 Which of the following expressions is correct for the molar conductivity of strong electrolytes 1 A m Am A c 2 2 Am A m A c 2 3 Am Am A c 2 4 Am Am A c 2 Ons 1 1 2 2 3 3 Question Type MCQ Question ID 1908891279 Option 1 ID 1908895049 Option 2 ID 1908895050 Option 3 ID 1908895051 Option 4 ID 1908895052 Status Answered Chosen Option 2

3 a The osmotic pressure of a sample of blood is 7 atm at 37 C Find the concentration of saline solution that is isotonic with the blood sample at this temperature b Why ethyl alcohol and water can t be separated into pure components by fractional distillation c Derive Duhem Margules equation stating clearly the assumptions 2 2 2

One mole of a real gas is subjected to a isobaric process from 2 bar 30 L 300K to 2 bar 40 L 500 K The molar heat capacity of gas at constant volume and constant pressure are 25 J K mol and 40 J K mol respectively What is the change in internal energy of the gas in kJ in this process

3 For a reaction A B products the rate c reaction was doubled when concentration of A wa doubled When concentration of A and B both wa doubled the rate was again doubled order reaction w r t A and B are 1 1 1 3 1 0 2 2 0 4 0 1

38 Iron is extracted from its oxide ores particularly haematite through reduction with carbon in a blast furnace The process id shown below zone slag 5000 zone 850 C 1000 C 130072 1900 C D C B 53 i Choose the correct options given below based on the process Mark only one oval A A Combustion zone B Reduction zone C Fusion zone D Slag formation A Combustion zone B Fusion zone C Slag formation zone D Reduction zone 1 point A Reduction zone B Combustion zone C Slag formation zone D Fusion zone A Slag formation zone B Reduction zone C Fusion zone D Combustion

Decomposition of di 2 methyl propan 2 yl peroxide produces propanone and ethane CH3 3COOC CH 3 2 CH3COCH3 C H6 The generally accepted mechanism for the above decomposition is Step 1 CH3 3COOC CH3 3 2 CH3 3CO Step 2 Step 3 CH3 3CO CH3COCH3 CH3 CH3 CH3C H6 K K2 K3 a Write down the expressions for the rates of change of concentrations of the intermediate s and the product C H with respect to time 3 b Derive a differential rate law for the rate of formation of the product C H on the basis of

For which of the following process AG 0 OA A g 1 atm 90 C B P of A at 1 atm 90 C O H O 1 H O g 1 atm 400 C O H 0 1 H O s 1 0 atm 10 C OA 1 A g 2 atm 90 C B P of A at 1 atm 90 C

Overall half life of the reaction is 15 days Then days if the ratio of ky k ky is 4 2 1 lodine 131 is a radioactive isotope If 10 mg of 1311 has an activity of 4 6 x 10 Bq what is half life of 131 1 in days The average life of a radioactive element is 72min Calculate the time interval in between the stages of 33 33 and 66 66 decay protes A B and C are isodiaphers while C D and E are isobars Calculate the difference of between A and EA B C D E Given Isodiaphers and isobars are formed in successive a and emission respectively In the given radioactive disintegration series ThPb Calculate value of n 2 Where value of n is number of isobars formed in this series suppose there is successive emission of B particles

SolveLancer Test Choose the correct statement for reaction 2A B zero order SolveLancer Test 1 Unit of k is moL L sec1 A o 2k 2 t A o k 3 Time required for 100 completion is 4 It may or may not be a complex reaction a All are correct b Only 1 2 and 3 are correct c Only 1 d None

B g C g and half life for the first o Half life for the zero order reaction A g reaction X g Y g Z g are equal If completion time for the zero order reactio 13 86 min then calculate the rate constant in hr for the reaction X g Y g Z g

nr Which of the following is not true regarding catalyst Catalyst does not change equilibrium constant value Coenzyme increases the catalytic activity of enzyme Catalyst can also catalyse non spontaneous reaction All of these

all steps to be elementary K A 2A K A B AB B K4 B A AB A Which of the following is incorrect k3 O DA dt dB dt k A 2 k A K4 B A dB dt K3 A B k3 A B K4 B A dA 2 k A 1 2 k A1 k A B KIBA l

A magnesium ribbon is burnt in the all t o give a white compound X accompani ed by emission of light If the burning ribb on is now placed in an atmosphere of nitrogen it continues to burn and forms a compound Y a Write the chemical formulae of X an d Y b Write a balanced chemical equation when X is dissolved in water

A gas P at an initial pressure of 100 cm of Hg is taken in a container of capacity V L P dissociates as P g R g S g At equilibrium total pressure is found to be 150 cm of Hg Now another gas Q is taken in a container of same capacity at initial pressure of 100 cm of Hg Q dissociates as Q g 2R g T g At equilibrium total pressure is found to 150 cm of Hg Find the partial pressure of R g at equilibrium in cm of Hg if both containers are connected by a thin tube of negligible volume T constant throughout Give your answer after dividing it by 10

13 A solution containing 1M XSO4 aq and 1M YSO4 aq is electrolysed If conc of X is 10 M when deposition of Y 2 and X2 starts simultaneously calculate the value of Z 2 303RT Given 0 06 F E x2x 0 12 V Ey2y 0 24 V 4 Molar conductivity of aqueous solution of HA is 200 Scm mol pH of this solution is 4 Calculate the value of pK HA at 25 C Given AM NaA 100 Scm mol A HCI 425 Scm mol A NaCl 125 Scm mol M

You are heating water in a pressure cooker provided with a temperature measuring device The initial water temperature is 30 C and the final steam temperature is 150 C Write down the changes step wise with relevant equations so as to calculate the total heat input required

Two gases A B are mixed under constant temperature condition Initial volume of gas A is 2 litre that of gas B is 5 litre When stop cock is opened then which of the following statements is are correct initials moles of gas A 2 gas B 5 2 litre Gas A 5 litre Gas B ASmix In 3 3 x ASmix 0 if gas A B are same and equal volumes of them are mixed OASmix n n R In2 if equal volumes of same gases are mixed AS max is maximum when equal moles of two gases are mixed Gas A B are different D

7 The vapour pressure of n hexane at 350 K is 840 torr and that of cyclohexane is 600 torr Mole fraction of hexane in the mixture that boils at 350 K and 1 atm pressure assuming ideal behaviour is 1 0 67 3 0 50 2 0 80 4 2 2

5 In the below experiment the value of P is Imol gas A 2 mol gas B 250mm 250 mm A 250 mm C 300 mm For a reaction Partition removed at same tem perature T B 500 mm D 400 mm Pressure P

Which of the following is true about concentration cells 1 Flow of electrons occurs due to difference in concentration of both half cell electrode or electrolyte 2150 3 F 4 Both 1 and 2 are correct

if an air bubble was trapped under the stopper when the flask filled with the unknown liquid was weighed the experimental density would be incorrect but one cannot tell in which direction too high too low

Which of the following reaction will not take place Select an answer A B Zn FeSO4 ZnSO4 Fe D 2KI Cl 2KCl I C Zn MgSO4 ZnSO4 Mg Mg CuSO4 MgSO4 Cu

Chlorobenzene M 112 g mol is stream distilled at 734 torr and 90 C The vapour pressure of chlorobenzene at this temperature is 208 torr The mass of steam required to distill 0 5 kg of chlorobenzene will be a 0 238 kg b 0 717 kg c 0 203 kg d 0 797 kg

There are two radioactive nuclei A B A is a emitter and B is emitter their decay constants are in the ratio of 1 2 What should be the number of atoms of each nuclei at time t 0 so that probability of getting of a and B particles are same at time 0