Physical Chemistry Questions

An ideal gas expands adiabatically against vacuum Which of the following is correct for the given process A AS 0 B AT ve 4 C CLAPEN A AS 0 B AT ve C AU 0 D AP 0 OG Age Refool XXI HERI C AU 0 D AP 0

7 15 mL of a 0 105 M solution of NaOH is titrated with 0 116 M of HCI solution 5 0 mL of acid is added to the solution What is the pH of the solution 1 58 13 1 12 7 1 3

2 Paragraph a N O g 3H g H O N H4 AH 76kcal b 4N g 3H O l 2NH3 g 3N O g AH 240 kcal c N H4 H O 2NH3 g 1 20 g AH 36 kcal d H O H g 1 20 g AH 68 kcal The enthalpy of formation in kcal mol of liquid N H4 is wer e Here er your answer here Back Space

Calculate the partition coefficient for the analyte when an unretained solute passes through a chromatography column in 3 7 min and analyte requires 8 4 min Assume the volume of mobile phase is 1 4 times than volume of stationary phase A 1 5 B 1 8 C 1 7 20

Two identical ideal gas samples an expanded from P V T to P by tw different processes 1 Reversible isothermal process II Reversible adiabatic process Identify correct option s W work done W I W II AU I AU II T 1 T II V I V II

Amount of heat evolved during complete combustion of liquid benzene can be calculated from the following data i 18 gm of graphite on complete combustion evolves 591 kJ heat AH H O ii 286 kJ mol iii The heat of formation of liquid benzene is 50 kJ mole Magnitude of heat evolved in kJ from

A system with charge no of electrons involved n is placed in an electric field with potential E volts Express the general form derivative expression with all the terms of Gibbs free energy function 5 pts

1 In the hydrogen reduction reaction change the chemical energy given energy into electrical energy multiple of potential E and charge 2 Explain why the Gibbs energy change GG in the hydrogen reduction reaction is arbitrarily zeroed to obtain the potential of a chemical cell 3 When the standard potential of galvanic cells is 0 76 V what is the standard Gibbs energy GGO in this reaction 1 2 3 H aq e 12 H2 g E O H H2 0 2 H aq Zn s Zn2 aq H2 g E O 0 76 V

The melting points of CCl4 at various pressures are given below along with the Molar Volume change for Fusion Calculate AHfus and ASfus at 1 atm and at 4000 atm P atm 1 1000 2000 5000 7000 2 t C 22 6 15 3 48 9 130 8 176 2 AV cm mol 3 97 3 06 2 51 1 52 S 1 08 1000 OF 259 1 Meral C OG TV all

6 7 Calculate the millimoles of Br produc 2 One gm of impure sodium carbonate is dissolved in water and the solution is made up to 250 ml 50 ml of this made up solution 50 ml of 0 1N HCI is added and the mix after shaking well requ 10 ml of 0 16 N NaOH solution for complete titration Calculate the purity of the sample imal places till you get the single digit answ

On heating copper sulphate crystals blue at a very high temperature it changes to white coloured substance X Number of water molecules lost by one formula unit of copper sulphate during heating is

When a solution of 30 0mL of 1 0M magnesium hydroxide at 25 0 C is added to 30 0mL of 1 1 M hydrochloric at 25 0 C in a coffee cup calorimeter the temperature of the solution increases to 33 5 C Assuming that the specific heat of the solution is 4 18 J g C and that the calorimeter absorbs a negligible amount of heat The density of water is 1 00g ml 250C Please write the balanced equation and calculate the AHneutralization in kJ mol for the reaction

72 The osmotic pressure of a solution of NaCl is 0 10 atm and that of a glucose solution is 0 20 atm The osmotic pressure of a solution formed by mixing 1 L of the sodium chloride solution with 2 L of the glucose solution is x x 10 3 atm z is nearest integer

For the reaction A B 2C If the initial concentration of all the reactants species is 1 M each then the equilibrium concentration of C is 1M The value of Kc of the reaction is assume only reactant initially present in the reaction

Methane gas CH4 effuses through a barrier at a rate of 0 340 ml minute If an unknown gas effuses through the same barrier at a rate of 0 205 ml minute what is the molar mass of the gas O 5 83 g mol O 44 1 g mol O 9 67 g mol O 0 171 g mol O 26 6 g mol

this sample of CuSO solution Molar mass of CuSO4 5H O 250 g mol liberated on addition of excess KI to CuSO solution What is the mass of CuSO 5H O in 250 ml of ml Na S O3 solution of 0 01 M requires 18 ml CuSO solution at the end point of titration with 1 a 2Cu 41 Cu I I 4 b I 2S O 21 S40 1 2 77 g 2 1 11 g 3 0 52 g 4 4 0 69 g

A flask of 1 5 L capacity contains 400 mg of O and 60 mg of H at 100 C Calculate the total pressure of the gaseous mixture If the mixture is permitted to react to form water vapours at 100 C what materials will be left and what will be their partial pressures

This section consists of 24 multiple choice questions with overall choice to attempt any 20 questions In case more than desirable number of questions are attempted ONLY first 20 will be considered for evaluation 26 The vapour pressure of pure solvent A is 0 8 mm of Hg at a particular temperature On addition of a non volatile solute B the vapour pressure of solution becomes 0 6 mm of Hg What is the mole fraction of component B in the solution a 0 25 c 0 50 b 0 75 d 0 35 0 2 of

When 12 0 mL of a 4 40 10 4 M aluminum acetate solution is combined with 25 0 mL of a 8 64 10 4 M ammonium phosphate solution does a precipitate form For these conditions the Reaction Quotient Q is equal to yes or no

For the first order parallel reactions starting with 1 M of A which of the followin statement s is are correct A B A2K2C AK 3D A B C D is independent of time B C B D t C C 0 67 M

1 Calculate the moles of 2 nitrobenzaldehyde and acetone 2 Nitrobenzaldehyde 0 5 g MW 151 12 g mol Acetone 5 mL MW 58 08 g mol d 0 785 g mL 2 Why is so much acetone used in this reaction Synthesis of Indigo

A 2 L flask containing nitrogen at 60 cm pressure is put into a communication with 4 L flask containing carbon monoxide at 48 cm pressure If the temperature is kept constant Calculate the final pressure of the mixture

Beaker A and B both contain 100 g of sol ution beaker A contains 28 g of solute X whereas beaker B contains 46 g of solute Y If after a long time beaker B was found to have a mass of 109 g then find the molar mass of X in g mol if the molar mass of Y is 23 g mol Assume only solutes are non v olatile and solvent is water

Compre The rate constant of reaction is related with T by Arrhenius equation Read the paragraph carefully and answer the following questio k A e fat Where k rate constant A Pre exponential factor or frequency factor e Fraction of molecules that is present in activated state E Activation energy Fraction of molecules that can cross the activation energy increases with increase in temperature or with decrease in activation energy R P Follows the above conversion graph and this first order reaction occurring at 27 C then if 102 molecules are in activated state Find the maximum rate constant A 348 10 day C 10 day B 3 46 10 day D can t be determined

aken as zero therefore If 150 kJ of energy is needed for muscular work to walk a distance of one km then how much of glucose one has to consume to walk a distance of 5 km Provided only 30 energy is available for muscular work The enthalpy of combustion of glucose is 3000 kJ mot Energy consumed for walking a distance of 5 km 150

of acetic Consider the titrimetric determination acid 60 05 g mol in vinegar Titration of a 5 00 mL vinegar sample requires 16 15 mL of 0 250 M NaOH to reach the phenolphthalein endpoint Which is TRUE when the endpoint is over run Choose from the following choices below A Acetic acid is in excess B Sodium hydroxide is in excess C Acetic acid and sodium hydroxide are of equal amounts D Cannot be determined

Which of the following is not an example of combination reactic a 2H g O g 2H O 1 b AgNO3 aq NaCl aq c C s O g CO g d CH4 g 20 g AgCl s NaNO aq CO g 2H O g

45 Equal masses of ethane and hydrogen are mixed in an empty container at 298 K The fraction of total pressure exerted by hydrogen is A 15 16 B 1 1 D 1 6 298 C 1 4 KATA A DRUGE SARGING B 1 1 A 15 16 C 1 4 D 1 6

At a certain temperature the vapor pressure of pure thiophene C4H4S is measured to be 207 mmHg Suppose a solution is prepared by mixing 102 g of thiophene and 74 1 g of benzene C6H6 Calculate the partial pressure of thiophene vapor above this solution Round your answer to 3 significant digits Note for advanced students you may assume the solution is ideal

A solution of 120 g acetic acid M W 60 in 2 kg water has the depression of reezing point equal to ATf Molal depression constant of water is Kf Ionisation constant of acetic acid is Assume molarity to be equal to molality AT K k 2 A C AT K k k kw AT K B D 2 kw k AT K Kw

37 Consider vaporization of CS according to the following equation CS2 1 CS2 g Calculate AG in kJ at the following conditions A 5 70 C 3 25 B 4 15 10 0 g CS 1 D 2 50 E 1 55 0 100 atm CS C

Various binders were investigated for the preparation of an analgesic drug tablet The disintegration of 19 Marks tablet was measured in a physiological buffer and the disintegration times are tabulated below From the information provided identify the binder that you would expect to generate the lowest spreading co efficient value of the buffer on the tablet Explain your answer Binder Povidone Gelatin Disintegration time min 17 0 23 5

which of the following is not the evidence fo r presence of aldehyhyde a Reaction of glucose with hydrooxxylamin e b Reaction of glucose with br2 c Reaction of glucose HCN

H g and O g can be produced by the electrolysis of water What total volume in L of O g and H g are produced at STP when a current of 30 A is passed through a K SO4 aq solution for 193 min 1 20 16 CO 19 2 40 32 A 90 64

A gas AB3 present in 10 It container at pressure 2 5 atm and 273 K temperature On increasing the temperature to 546 K AB3 dissociates into AB g and B g If the degree of dissociation of AB3 is 0 8 then final pressure at 546 K is

of different half cells are given red o E 2 Cut2 cu 0 34 V E Zn 2 Zn 0 76 V A Ag Ag 0 80 V E Mg 2 Mg 2 37 V n which cell is AG most negative A Zn Zn 2 1M Ag 1M Ag B Cu Cut2 1M Ag 1M Ag Agt 1M Mg 1M Mg C Ag D ZnZn 2 1M Mg 2 1M Ma

0 224 litre Os gas at 1 atm 273K expanded adiabatic reversibly upto 8 times of its intial volume then magnitude of work done in process will be in cal vibrational modes of energy are inactive Give your answer as nearest integer

By calculating ASuniv at each temperature determine if the melting of 1 mole of NaCl s is at 500 C and at 700 C spontaneous S NaCl s 72 11 mol K S NaCl 95 06 mol K kJ mol AHofusion 27 95

A sample of hard water contains 2 mg CaCl and 2 mg MgCl2 per liter Calculate the hardness of water in terms of CaCO3 present in 106 parts of water Molar mass of CaCl 111 g mol MgCl2 95 g mol and CaCO3 100 g mol O 1 95 ppm O 2 50 ppm 3 90 ppm O 1 25 ppm

2 A sample of O is collected over water at 22 C and 748 torr pressure The volume of the gas collected is 82 0 cm How many grams of oxygen are present in the gas Vapour pressure of water at 22 C is 19 8 torr

You want to compare brands of paper towels to see which holds the most liquid Independent Variable Dependent Variable You want to know whether caffeine affects your appetite Independent Variable

b H C CH CoCl H N CC NH H O H C CH COC H N CH CH NH HO ii For each of the pairs of reactions below answer the following questions I What type of substitution reactions are they II Which mechanism are the data consistent with dissociative or associative mechanism Explain Fe H O H O Fe H O H 0 iii trans Co NH Br en HO trans CoBr en k 3 2 x 10 k 5 4 x 106 s k 6 0 x 10 s H O k 3 2 x 10 s k 1 2 x 10 sl k 1 4 x 10 H C CH CoCI H O H N C C NH CT H C CH CoCI H O H N CH CH NH CF Fe H O H 70 H O Fe H O H 70 H O trans Co NH H OKen B trans CoBr H O en Br

nsider a 100 gm oleum sample which is labelled as 110 H SO4 After adding only sufficient amount of water that can react only with 3 If x grams of pure H SO4 can be obtained from the solution Then the value of x 100 is 2

At 25 C the osmotic pressure of a blood sample due to presence of various solutes in it is 7 65 atm Assuming that molarity equals molality calculate the freezing point of the blood sample K 1 86 K kg mol and R 0 0821 litre atm K mol LO 5

PIA D A C In above diagram A has five valence electrons and B C and D have six valence electrons each According to the L D S A has x formal charge B has y and C has z formal charge The above mentioned compound ion follows Lewis octet theory Give the answer of following question if A B C D belongs to p block Identify the formal charge of A B and C respectively

An equilibrium PC g PCI g Cl g is maintained at given temperature in a cylindrical system with movable piston The concentration PCI 5 PCI3 and Cl are found to be 0 01 0 4 and 0 4 mol L respectively In this system 4 moles of Cl 8 moles of PC are added and 0 2 moles of PCI3 removed which changes the volume by x times What will be value of equilibrium constant at new condition

Which of the following condition is are favourable for the production of NH3 g according to following reaction N g 3H g 2NH3 g assume system initially at equilibrium Increase in pressure of system Increase in volume of system Introduced more amount H g Introduced more amount N g

Solutions 109 1 kg of an aqueous solution of sucrose is cooled and maintained at 4 C How much ice will be separated out if the molality of the solution is 0 75 K H O 1 86 kg mot K Since molality of solution is 75

In all other cases For Example If first third and fourth are the ONLY three correct options for a question with second option being an incorrect option selecting only all the three correct options will result the three correct options e g the first and fourth options without selecting any incorrect option second option in this case will result in 2 marks Selecting only one of the three cora fourth option without selecting any incorrect option second option in this case will result in 1 marks Selecting any incorrect option s second option in this case with or without sele result in 2 marks A gas mixture contains 1 mol CH and 2 mol SO3 correct statements are 0 Average molar mass of the mixture is 176 6 change in average molar mass of the mixture if SO3 is completely dissociated in SO and O 25 Mass ratio of CH and SO3 Initially present in the mixture is 1 10 If 1 mol more CH is added in the given gaseous mixture then new molar mass of the mixture is 48

i Explain the formation of peaks at 128 100 86 71 57 and 43 in the El mass spectrum of 4 octanone ii What is meant by DEPT and what are its applications iii Explain how simplification of complex proton NMR spectra can be done by increasing field strength and lanthanide shift reagents